Title: To Be Left Behind
A/N: My first crossover between Narnia and Doctor Who, as well as my first time writing Doctor Who at all. Recently reposted to fix the line break issue.
The Armogol had been successfully taken care of, and now the only thing left for the Doctor to deal with was the girl. She was sitting stiff and silent on the park bench, her nylons ripped and a heel broken from her shoe, and a trail of black on her cheek betrayed the wiped away tears. She was just an ordinary girl with dark hair and red lips, with slender typist's fingers and narrow, cynical eyes. If he had to guess, she was the secretary of some important business man, making just enough to keep herself fed and dressed smart.
The girl was just an unfortunate citizen caught in the disaster, and while she did not appear to be hurt, it was quite clear the situation had been traumatising for her. Normally, the Doctor would leave the cleaning up to others but there was no one else in the park, so he knelt down in the dirt at her side and took her hand carefully.
Her head jerked up and her arm tensed, but the girl did not try to pull away. The Doctor studied her face and saw that she was older than he'd first thought, for she'd covered well the worry-lines that crossed her forehead and creased her eyes. Not so much a girl, then, but a woman.
"It's all right," he murmured soothingly. "Nothing to worry about. I took care of it- see? All gone now." He was saying some stupid things but it didn't really matter, for it was the tone that counted. Like talking to wild horses or crazed Tarveks.
He expected her to burst into tears at any moment, or else ask some bewildered questions along the lines of, "What was that thing?" or else exclaim over the fact that it had been aiming to kill her. But she didn't. Instead, the girl took a shuddering breath and stated, "That was a satyr."
Satyr? That would be Greek mythology, or Roman – he always got the two mixed up. Maybe it was from something else entirely. All the same, it was some sort of ancient mythology.
"Ah, yes. Armogol, actually. Can see how you got mixed up. Body of a man, legs of a goat, that sort of thing."
She frowned at him with irritation. "It was a satyr; I know, I've seen them before."
"And where would that have been, eh?"
She looked away quickly, as though only just remembering something. "Never mind, it's just a story. They shouldn't exist at all." Her soft brown eyes flashed to his face again. "What did you call it?"
"An Armogol. Comes from a planet half-way across the galaxy. Lovely place – they make excellent Danishes."
"Halfway across the…" the girl mouthed and then shook her head violently. "I'm going mad, aren't I? Or else you are."
"I'm mad, you're mad, we're all mad here," the Doctor said with a grin.
"Alice in Wonderland?"
"Bingo!" He rose off his haunches and smiled brightly. "I'm the Doctor, by the way. And you are-?"
She didn't question his name, which made him like her all the more. She gripped his hand tight and shook it politely, obviously recovering quite nicely from the scare, and replied, 'Susan the-" The words were interrupted as she swallowed whatever she'd been about to say and finished quickly, "Susan Pevensie."
"Well, Susan the Pevensie, you sound as though you've seen an Armogol before. Care to take another look?"
She pulled her hand from his and looked quickly away, and when she turned back her eyes were shining with unshed tears. "The satyrs, you mean? Armogols are what you call them?"
He nodded pleasantly and held his hand out. The offer hung between them like an enticing apple. Judging by her expression, there was more to this choice than he thought. The Doctor was unable to tell just what it was, but Susan-the-Pevensie seemed weighed down by life far more than he would have expected. She was wavering, he could tell, but when her fingers touched his palm it was with sure decision.
"Show me the satyrs," she requested.
He could count the number of people on both hands who had not commented on the TARDIS's bigger-inside-than-outside size and still have fingers left over, but Susan-the-Pevensie was one such person. She stepped through the doors and stroked the coral pillars and murmured something about a wardrobe, and that was it.
"To the planet of the Armogol, then?" he asked, hands hovering over the controls.
Rather than agreeing, she circled the console slowly, her gaze intent and inquisitive. "Tell me," she asked slowly, "Does this count as you kidnapping me?"
His hands dropped to his sides. "I don't know. Are you coming willingly?" Maybe she did not want to come after all.
Oh. Well, then, "Anyone to miss you?"
She shook her head quickly. "My employer," she said with distaste, almost as an afterthought. He gathered she did not care whether her employer missed her or not.
She shook her head again, a frown creasing her forehead, and changed the subject abruptly. "This planet we're going to – how far did you say it was?"
"Halfway 'cross the galaxy, give or take a couple light years." His hands rose to the controls again. "Ready to go?"
A smile crossed her face, which was all the confirmation he needed. With a shout of glee he pulled some levers, pressed some buttons, turned a knob, and they were off.
"How long is this going to take?" she shouted over the sounds of the engine.
"Oh, couple o' minutes, not much more than that."
The look on her face was like a child on Christmas morn. "Magic," she breathed.
"Science," he corrected, and lifted his chin proudly.
It was supposed to be a one-trip deal, but after he and Susan had eaten their fill of Danishes and met enough of the much-too-hearty Armogols, he found himself offering a trip to Ancient Greece "to hear the myths first hand".
"You see," he explained as the TARDIS came to a rest on top of a thoroughly Greek hill – unless he made a mistake and it was thoroughly Roman instead. "It was a couple of lost Armogols that started that whole string of myths. Took a wrong turn, stopped to ask for directions, took off again – and the legends were born! Brilliant stuff, wouldn't you agree?"
"Perhaps there was a doorway somewhere here," Susan was muttering to herself.
The Doctor raised an eyebrow in question, but she shook her head coolly and walked on. He could have pried, but it was sort of nice not being the only one keeping secrets. Rather refreshing and all.
"I thought you were taking me home after Ancient Greece," Susan commented idly, glancing behind her at the large, metal door.
"I thought you wanted to see more," the Doctor retorted. There was a hum as he held the screwdriver over the wires with the hopes that he could fix the circuit. "You made no complaints at the last three stops."
"We weren't exactly being chased then, were we?" Susan shot back. The door buckled and the bolt broke, and there was a large, orange something waving its tentacles at them from the doorway.
Susan reached into her pocket and pulled out a knife that the Doctor hadn't even known was there. Fast as lightening she sent it zipping through the air to strike the creature in the center of its single eye. There was a wail, the tentacles flailed, and it died.
"Good aim," the Doctor complimented as Susan stepped past the tentacles to retrieve the dagger. She wiped it with care and precision on the back of her trousers and slipped it back into its sheath.
"Lucy was always better," she replied, and although the Doctor wondered, he did not ask who Lucy was.
"See, it's a trick us Time Lords have. We change our face, our body, our personality… we become a whole new person, only with all the experiences and memories of the old still locked away inside. A way to cheat death."
"So then, it's like you become young again?"
"Sort of, yeah."
"And then no one believes that you really do know what you're talking about, because you look like you're barely old enough to understand. So you have to prove yourself all over again."
"You sound as though you know what it is like."
"Well, sort of, yeah."
Sometimes he would catch her sitting in a corner of the TARDIS, not doing anything at all. She'd be staring at nothing, her fingers stroking a chain about her neck as she waded through old memories. He'd leave her there, careful not to make a sound lest her indifferent mask again slip into place.
"You must miss them," he said once by complete accident. He hadn't meant to speak at all, and at his words her face closed up. Three seconds passed by – tick, tick, tick – as she studied the panel behind his head, and the Doctor fully expected her to ignore him.
But she didn't. "More than you could imagine," she said softly, her fingers rising to her neck. "They died in a railroad accident a few years back. My entire family died in one instant because of a cruel twist of fate, and suddenly I was alone."
Oh, but not more than he could imagine at all! "You must have been close."
"Once upon a time. And then I went and made an idiot of myself." Her voice hardened with self-scorn. "I made a mistake and I was too stubborn to admit that I was wrong."
It was one of those deafening silences that made the Doctor's fingers itch for action of any sort. He longed to say something, but anything he thought of sounded superficial and insignificant.
"We never made up," Susan whispered.
His fingers were twitching. He knew he shouldn't; knew it was a bad idea, but all the same… "Would you like the chance?"
It was late summer of the year 1949. Surprising heat rose from the roads and walkways, and clouds of smoke hung heavy above the railway station. Susan's hand tightened around his own.
"Remember," he said slowly and deliberately, "You cannot save them. It will change the entire universe. I once took a friend to be with her father the moment he died – she changed events and saved his life and nearly tore apart reality itself. You cannot save them. Understood?"
"I promise," she said quickly, straining forward, but still he did not let go. The Doctor did not know why he was doing this – it could spell out all sorts of disasters.
"I promise, Doctor," she said again, and he could hear tears in her voice. Slowly, he let his fingers loosen. "Thank you," she whispered.
He watched her walk to the train station and followed, not close enough to intrude, but near enough to keep an eye on things. Susan walked briskly forward, chin raised boldly and hands in fists.
He wondered what it would be like if he had had the chance to say goodbye.
Her hand wrapped tightly around the door to the station, but just before she could open it, the Doctor saw her resolve crumble. Or – no, crumble was not quite the right word. Her resolve shattered, and she fell to her knees beside the door in a rush of tears. He could only watch dumbfounded as she cried, the people on the street casting strange looks in her direction but moving on without offering aid. Perhaps they thought this was yet another consequence of the war that had ravaged across the planet only a few years before.
Seconds, and then minutes, passed as the Doctor waited helplessly. Finally, Susan pulled herself to her feet, wiping her face self-consciously on her hands before taking hold of the door-handle once more. Then her fingers slipped off, and she turned and ran past him down the street to the TARDIS.
She was choking on tears again when he joined her at the door. There was a certain lack of ceremony as he handed her a TARDIS key, but her fingers were shaking too hard, and he had to take it back to unlock the door. A screech of metal filled the air behind them. Susan froze in shock, and the Doctor pulled the door open quickly - but not quickly enough. The horrified screams had begun.
The next afternoon was spent on Turnmole, which was usually a sure bet for adventure but this time left them locked in a cell for over an hour with nothing but their thoughts and the Doctor's meaningless words. He tried to fill the silence with as many explanations of the planet and its culture as possible, but eventually even he could think of nothing more to say. So much for a distracting adventure.
Susan had been quiet for much longer than he would have liked, and as their executioners came for them she said softly, "I never apologized to Lucy."
You never apologized to the others, either, the Doctor added silently, but said aloud, "I guess we'll have to do something about that."
It always surprised him how fast humans could run when properly motivated.
The telephone was ringing noisily in her ear, and the Doctor could hear it even from his position on the other side of the TARDIS. Susan's knuckles were white where she gripped the phone as though holding on for her life.
"How do you know she'll be near the phone?" Susan hissed worriedly, twisting the cord around her fingers.
He'd checked and double-checked, but before the Doctor could assure her of this, someone answered. Susan's face drained of colour. "Lucy?" she choked.
He could not hear specific words but the voice on the other end sounded high pitched and worried. Susan was taking deep breaths to steady herself – it was obviously harder for her to do this than she would have expected.
"Lucy," Susan said again, this time with more strength. She was slipping into her regal form again – the one that the Doctor never could see coming, but always could recognize when it was there. "Lucy, I love you."
There was a reply on the other end and Susan's knuckles became even whiter. "N – no, Lucy, everything's fine here. I just – you can't -" Her face drained of colour. "I love you, is all."
The voice said something back. "Goodbye," Susan whispered, and slammed the phone down hard.
She stood panting and crying, and the Doctor was at her side in an instant, helping her across the room to the empty couch that stood ready. It was clear Susan was taking no notice of her surroundings, for she stumbled twice and practically collapsed onto the cushions when they got there.
"I was going to tell her," Susan gasped as she wiped fiercely at her eyes. "I almost told her. I had to hang up, I had to, or else I would have told her-" Her words dissolved into a flood of tears.
The Doctor sat beside her and let her head rest on his shoulders as she cried out all her pain.
They flew to Zarbon and Corith and Newt; visited Queen Elizabeth, Alexander the Great, and Noah's Ark; fought Mumifferifs, Eckno, and Daleks (again!). All the time, Susan said not one word of her past, and the Doctor asked no questions. It was a truce, of sorts, but an uneasy one; Susan would cast side glances in the Doctor's direction as though both hoping he would ask and praying he wouldn't, as the Doctor tried to decide whether they'd skirted the issue for too long. But the unofficial truce was held, and the TARDIS took them to busy planets, where there was no time to do anything but run and fight and shout and fight and run.
It was on Tathock as they were running for their lives (yet again) across the desert dunes that Susan gasped out, "The TARDIS can go anywhere, can't it?"
"Well, it can't come to us, if that's what you're asking."
She shook her head tiredly and an extra spurt of energy brought her up to the crest of the next dune. The Doctor followed close on her heels, with the native Tathockians only a short distance behind.
"Can it take us to other worlds?"
He spared a brief second to look around pointedly. "This is another world."
"I mean another… place. Another reality."
"Don't you think this conversation would go better if we were sitting down with a cup of tea? Tea's good. I like tea. Also like running, but running's not so good for talking and drinking tea."
She pulled a face at him and with another burst of energy from some hidden reserve she pulled ahead again. He watched enviously as she drew away, and wondered how she could be so much more in shape than him.
"There are plenty of parallel universes out there," the Doctor began, once they'd returned to the TARDIS and made tea. Susan was curled up in the chair opposite him, and although she was cradling her tea with both hands, it looked rather as though she'd forgotten it already. "Whenever some incredibly big choice is made, a separate universe springs up - a sort of could-have-been world. But it's impossible to travel to these other universes without ripping holes in the fabric of reality, and I mean that quite literally."
Susan nodded intently, but her forehead had creased. "Parallel universes - but those are still similar to our world, aren't they?"
The Doctor pictured again giant blimps in the sky. "For the most part, yes," he agreed reluctantly.
She was shaking her head slowly at him. "But what about other worlds? Entirely different universes - not parallel, not perpendicular, but completely different."
"There isn't any such thing."
Susan absently ran her finger around the rim of her cup. "There is. I know; it has to be. Otherwise I dreamt it all and after everything I've seen..."
"We were in the country," she explained slowly, "It was during the war - the second world war. Lucy found a wardrobe, and we stumbled through it and into a whole different world with fauns and centaurs and talking beasts and... we ruled there. For fifteen years we ruled, before coming back to find that no time had passed at all." She looked up as though daring him to disbelieve her; both knew he'd seen too much to ever do such a thing, but Susan seemed to fear he might all the same.
"No time had passed?" the Doctor mused, rubbing the back of his neck. "What did everyone say when you suddenly grew fifteen years overnight?"
"We didn't," she said simply.
He opened his mouth in a silent "ah" of understanding. "You became young again. Right. I see. And it was a whole other world? A whole different universe?"
"The world was flat, and the stars were living, and there was magic."
He did not doubt her words, although the mention of magic gave him pause. The ability to harness energy in order to control it so completely... it should be impossible. (But she had said it was a whole different world).
"And you want to know if the TARDIS can go there?"
She did not answer, but that was answer enough. The Doctor pressed his lips together and looked away. "It won't work."
"But you could try."
"I could try, but it won't work. The TARDIS can't detect other worlds - the only way to get to a parallel universe is by falling into it, and I doubt it's different for your world."
He could see her heart break just a little at his words. She'd so obviously spent a lot of time working up the courage to ask him, and now for him to shut it down so quickly must be nearly unbearable.
"I'll see what I can do," he promised.
It didn't work. The Doctor went back in time to inspect the wardrobe Susan had mentioned, and then to study a certain train station, and then to test a painting hung in an old spare room. None of them showed any energy readings beyond the norm.
"I'm sorry," he said quietly, after his last idea had turned into yet another dead end. "I think the only chinks to your world have been sealed."
Susan nodded once and asked if they could visit the Eiffel Tower. He took her to the moment it first opened for tourists.
Really, the Doctor should have known that whenever Jack Harkness turned up it would lead to trouble - trouble involving pesky Albite officials, death technicalities, and flirting. A whole ton of flirting. It seemed as though every time there was the slightest pause in the action, Jack would start sweet-talking Susan yet again.
And the worst of it: Susan was flirting back.
It was subtle, of course, especially compared to Jack's over-the-top style, but the Doctor knew the signs. He'd certainly lived long enough to recognize flirting when it happened, and this entire adventure was full of smirks and winks and side comments with double meanings. The Doctor was beginning to feel quite annoyed over it, and it wasn't because he was jealous (because he most certainly was not). No, it was just - Jack. Flirting with Susan. Who was flirting back.
The worst of it was the goodbye, filled with "I'll see you again"s and "not if I see you first"s, while the Doctor could only stand helplessly at the TARDIS door. There was another smirk, a cheeky wave, a wink, and then-
It was all back to business for Susan.
The Doctor felt almost as though he had just stepped forward to another time zone. Had she really just removed the flirtatious manner as easily as he took off his overcoat?
Susan cracked a smile when she noticed his stare. "When you've grown up ruling a kingdom, and then you grow up again in England, and then you travel through space and time, you learn when certain aspects of your personality are most appropriate."
"Well, I'd noticed the personality shifts before, but I've certainly never seen you flirt."
"But then, you aren't Jack," Susan retorted.
The moment Susan entered the TARDIS control room, the Doctor knew he was in trouble. He'd come to recognize over time that whenever Susan got a certain look in her eye, accompanied by a certain change in her posture that he couldn't really identify but knew was there, she was about to ask for something. Given how little Susan asked for things, the Doctor could pretty nearly guess what she was about to ask him, and he wasn't sure whether he liked it.
"I never even went into the train station," Susan began slowly, resting her hand on the edge of the console. "I never even opened the door."
"True," the Doctor conceded, the mention of the train station confirming his prediction.
She was looking everywhere except him, as though ashamed by her request. "If the TARDIS were to land on the platform itself, we would never be seen by our other selves. Our past selves, I mean. Or at least-"
"I know what you mean," the Doctor interrupted.
She took a deep breath and stared intently at the coral behind his head. "So if we were to go there, it wouldn't exactly count as crossing timelines. And then I could say goodbye for good."
He nodded, allowing her this point as well. Susan took another deep breath and held it, waiting anxiously.
The Doctor knew they shouldn't be doing this. It had been bad enough the first time, and when Susan had lost her resolve he'd felt a certain amount of relief that she was not going through with it. Interfering with events, even if only to say goodbye, should be an automatic no. When doing so at the same time as another Doctor and another Susan were standing just outside was even worse.
"You know you can't save them," the Doctor warned, and Susan blinked in surprise at the almost-agreement.
"I know. I promise I won't. Please, Doctor."
One day he was going to get in trouble for going along with his companions' wishes so often. The Doctor leaned over the controls and pulled back a switch. "Next stop: England, 1949."
It was late summer of the year 1949. Surprising heat rose from the roads and walkways, and clouds of smoke hung heavy above the railway station. Susan's hand tightened around his own.
Across the platform stood two young men in workmen's overalls. The Doctor could see the resemblance to Susan immediately in the shape of their face and the colour of the younger man's hair.
Susan stifled a gasp.
"You can't save them," the Doctor said sternly, and held her hand tight until she raised her eyes to his face and nodded solemnly. With that, he loosened his grip and she started toward her brothers.
There was a certain prickling at the back of the Doctor's neck, one that usually came to him only when something bad was going to happen. He stepped forward to stop Susan, and then remembered the way she had looked at him and knew she could control herself. The prickling continued.
He knew he couldn't leave her. Something could happen at any moment and the Doctor needed to stay for damage control, just in case. All the same, he spun about slowly on his heels, taking in the few other people waiting on the platform, the wooden slats of the platform, the empty tracks. Something was about to happen.
It occurred to him that it could just be the crash that he was sensing. The Doctor allowed his shoulders to relax and looked over to Susan. Rather than already be at her brothers' side, she had stopped half-way across the platform and was looking back at him. Had she lost her nerve again? If she didn't work up the courage, she'd never get the chance to say goodbye.
Then he saw her white face and fierce eyes and the outstretched hand that pointed to the corner of the platform. "DOCTOR!" she shouted, and before he even could register this completely, he'd spun about and seen it.
There was an Armogol on the corner of the platform, and beside it, what looked to be a giant snake with a humanoid head, arms and legs - a Coricle. Worse, the aliens seemed to be having a stand-off, for both held blasters pointed at each other. At their feet was a black box.
No one else in the station had seen them yet, but it wouldn't be long until they did. The Doctor took off at a run.
The Armogol spotted him first, because the Coricle was facing the opposite way. But then the snake-thing turned and hissed at the sight of the Doctor, and suddenly both blasters were pointed at him.
Why did this have to happen now? The Doctor lifted his hands in a show of peace and moved toward the aliens cautiously. "Look," he began, "I know you two are in the middle of something here, but there's about to be a railroad accident and you're both going to be killed."
The snake hissed at him, and the Armogol took the opportunity to scoop up the black box and bolt over the edge of the platform to the tracks below. With a cry of rage, the Coricle followed.
"No, no!" the Doctor shouted, and took off after the pair. He could hear Susan crying his name back on the platform, and paused just a minute to look back. She had run to the edge of the platform and was looking down at him fearfully. "Look, Susan, I'll handle this. You do what you came for."
"But what's happening?"
She was becoming hysterical, he realized, and explained rapidly, "Black box contains stolen goods. They're fighting over who gets to keep it. Judging by the blasters, this could turn into a very ugly shoot-out if I don't stop them in time."
"I'll help you," she promised.
"You do what you came for," the Doctor said again.
She began to nod slowly, and then her eyes opened in shock and the Doctor felt an explosion of pain on the back of his head. He tottered for just a moment before crumpling to the ground. Dimly, he heard the Coricle's hiss from above, and Susan's shout of terror. Forcing his eyes open, the Doctor registered Susan as she fell to her knees at his side.
What was she doing? He was fine; he didn't need help. "Go see your brothers."
She ignored his words and helped him to his feet. The Doctor took one step and felt his balance slip away from him; he would have fallen again if Susan had not still been holding his arm.
"I'll stop them," she told him calmly.
What? No! "Go say goodbye to your brothers."
"You said it yourself - this could end in a very ugly shoot-out."
"I'll stop them."
"You can barely stand."
He gritted his teeth in irritation. "It's just a concussion. I'll be fine in a minute."
"Just a concussion!"
They were spending too much time bickering, and the aliens were getting further away while the train was drawing near. He could feel the vibrations of the track now - they didn't have much time.
"Susan - this is the last chance you have to see your brothers. We can never come back."
"I'm made my decision," she snapped, and let go of his arm. The Doctor felt himself wobble, but tried to hide it. "Get off the tracks," Susan directed. "I'll stop them."
With a scowl, Susan took off at a run in the direction the aliens had gone. The Doctor moved to follow, and although his balance was still skewed, he was able to manage a strange, stumbling lope. Right outside the station, there was a bend in the railroad tracks - the bend, he remembered, that the train would take too fast in only a couple of minutes. And there, right at the bend, were the aliens, both pointing their blasters at Susan.
A loud roar was filling the air, and the vibrating tracks were nearly rattling. The train was coming; it was almost upon them, and Susan and the aliens were right in the middle of the tracks.
"No!" he shouted, and Susan looked back in alarm at the train. There was no time for the Doctor to reach her. With a squeal of brakes and the loud crack of a blaster, the train was at the bend. The Doctor dove off the tracks, ducking into a roll just as the train roared past. Then it was gone, and the Doctor could only listen helplessly to the shriek of crumpled metal and the screams.
Susan! The Doctor tried to stand, and found that his concussion had worsened. All the same, there was no way he was leaving her. With unsteady feet, the Doctor ran to the tracks, half-expecting to find her broken body right there. See - there was the Armogol, and beside it, the Coricle. Both dead. The Doctor turned away in disinterest. Susan - where was Susan-?
He turned around and there she was, bruised and tearful, with a shaky smile in careful position on his face. The Doctor pulled her into an embrace and offered what comfort he could.
"You know, Doctor – for all that my brothers were kings and warriors, when in England they weren't at all very good at seeing what was right under their noses."
The Doctor thought back to the platform station and the oblivious men waiting in their workmen disguises, their hands in their pockets. "Well, they are British. And human. You humans never seem to notice anything important unless it directly affects you."
She wrinkled her nose at him and tapped her knee thoughtfully. "But don't you get it, Doctor? It did directly affect them." She nodded to the unopened black box that sat enticingly on the console. "I always wondered why no one ever found the rings, and now I know."
"You mean-? No. It couldn't be."
She nodded, a little smile lighting her face. "The Armogol stole the box. Or the Coricle – one of the two, at any rate. You said yourself there were some terribly strange energy readings coming from the box. The aliens must have been drawn to it."
He stared at her in amazement, trying to decide whether it really could be possible. Surely not, but if it was – "And you think the TARDIS could trace the energy signal?"
She pressed her lips together as their minds exploded with possibilities. To go anywhere – any world, any universe – explore forever...
And then Susan stood and lifted the box from the console. "What did you say we were orbiting?" she asked carelessly, stepping across the room to the TARDIS door.
"A black hole," he supplied.
She opened the door and paused for just a moment to gaze on the strange beauty of the gaping hole. Then Susan lifted her arm and tossed the black box from the TARDIS to go spinning to its destruction.
"Why do we need other worlds," she asked slowly, pulling the door closed with a sense of finality, "when we've already got this one?"
When Susan stepped out of the TARDIS for the last time, there was a spring in her step and a smile on her face. The air was fresh, as though it had just finished raining (it probably had), and the Doctor found it hard to imagine that it was only the day after the Armogol incident that brought them together for the first time.
"Goodbye, Susan-the-Pevensie," he said, and pressed a smile to his face.
"Thank you, Doctor," Susan said lightly, and she started off down the road. She was humming a tune to herself that he thought she first heard in Ancient Greece, but he couldn't be sure. She didn't look back once, which was odd, because usually the Doctor's companions would wait to see him off. This time it was the Doctor seeing his companion off, and he found it to be a refreshing change.
Only when Susan had disappeared into the bustling crowd did the Doctor sigh once before stepping back into the TARDIS and closing the door. He circled the console once, twice, and paused beside the screen as he tried to think of a place to visit.
Then with a flurry of lightening movements, the Doctor sent the TARDIS hurtling away from London and far into the future.