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AN: This takes place towards the end of Day Five of "Children of Earth", in the warehouse where Jack, Dekker and Johnson are preparing to transmit the wave that will destroy the 456, just after Alice had been dragged out of the main warehouse area but before Steven was brought back, although things significantly diverge from canon after that…

The Champion of the Children

As Jack stood behind the console that would transmit the signal, staring grimly at the place where the focus point- he couldn't think of what would really be there or he wouldn't be able to bring himself to do this- would be standing soon, he wished he didn't have to do this.

It was all so… rushed; if he only had the time to think of something else he could do instead of this…

But, at the same time, he knew that he didn't have a choice; without a medical or technological expert of his own- he wasn't exactly stupid but Tosh and Owen had forgotten almost as much about those fields as he'd ever learned-, all he had to go on was Dekker's 'advice' on how to transmit the signal, and he only had a matter of minutes left to him before his chance to save the kids the 456 were about to take ran out.

He couldn't place one child above the whole of humanity…

In that moment, more than ever before, he understood how the Doctor must have felt when he was forced to send Martha out into the world during the Year That Never Was-

He stopped.

Was that his imagination getting desperate, or did he hear…?

Looking over in the direction of the sound, his eyes widened at the sight before him; a large blue box, gradually wheezing its way into existence right in front of him, the light on its top flashing on and off as it solidified inside the warehouse.

"What the…?" Agent Johnson said, turning to look at Jack in confusion, only to pause at the smile on his face. "Is this… you know about this?"

"Know about it?" Jack said, unable to stop the broad grin on his face as he looked over at Johnson. "Lady, that box holds the one man capable of doing this job way better than I-!"

His smile faded as the door opened and a short man dressed in a brown jacket and a sleeveless pullover covered with red question-marks stepped out of the ship, a straw hat on his head and a red-question-mark-handled umbrella over his arm, closely followed by a young woman in a bomber jacket covered with an almost ridiculous number of badges.

Jack had never seen this man before, but he had a sneaking suspicion he knew who it was…

"Ah, hello," the man said, turning to look at Jack with a smile as he raised his hat. "I'm the Doctor, and this is my friend Ace; would you happen to know why the last few days have been sealed off from vortex travel?"

"Doctor?" Jack repeated, walking around from behind the desk to look at the man with a renewed sense of discomfort; what had happened to the Doctor he'd met last time?

"Yeah, he already said that, mate; who're you?" the girl- Ace?- asked, glaring over at him. "Look, we've got to a lot of bother just to get here; can you at least tell us who you sods are?"

"Ca… Captain Jack Harkness," Jack said, looking briefly at Ace before walking around the console to stand in front of the man who'd introduced himself as the Doctor. "Doctor, it's me; don't you remember?"

"I'm really afraid I don't-" the short man- Jack couldn't get how this guy could be the Doctor; how could he have shrunk like this?- began, looking uncertainly back at Jack.

"Come on!" Jack said, clasping the man's shoulders as he crouched slightly to look the other man in the eyes. "Rose Tyler, Martha Jones, Slitheen, Daleks, the Master, Donna Noble, Sarah Jane, Davros… you can't tell me that all that's slipped your mind?"

"Hold on; you know Davros?" the little man replied, stepping back slightly to glare at Jack. "How can you know about him; he hasn't come to Earth in this era…"

He paused mid-sentence, his eyes widening as a small grin spread across his face. "Of course…"

"What?" 'Ace' asked, looking at her companion in confusion. "What is it, Professor?"

"It would appear, Ace, that Captain Harkness here is someone I will know in my future; we've simply met him out of sync," the short man replied, nodding briefly at her before looking back at Jack. "And, judging by the fact that you didn't start out this little meeting by saying that I couldn't be me, shall I take it that you're aware of my ability to regenerate?"

"Well… yeah…" Jack said, suddenly growing ever more uncomfortable as he realised the implications of what this man was saying to him; if this guy was the Doctor, but he didn't know about Jack…

"You're… you're him before he knew me, aren't you?" Jack asked, already wondering how he should feel about the implications of this guy being here; even if the Doctor before him left right now, wouldn't that mean that 'his' Doctor- the Doctor in the pinstripe suit and the coat he'd received from Janis Joplin- would know what was happening here…?

"Yes, it would appear so, Captain… Harkness, wasn't it?" the man- the Doctor- replied, shaking his head slightly before he turned to look more pointedly at Jack. "And on that topic, I don't suppose you'd be willing to explain what's… different about you?"

"Different?" Jack repeated, raising his hands slightly as he tried to feign nonchalance; he'd known that the Doctor he knew found it difficult to look at him, but for this other Doctor- a younger Doctor- to see… whatever it was that he looked like to a Time Lord… as well…

The sound of a door opening prompted the Doctor and Jack to turn around, just in time for Jack to see Steven being carried into the room by one of the soldiers, the door slamming shut behind them just as Alice's face became visible; Jack almost wished he could shoot himself and make it stick rather than have to face the pain on his daughter's face…

"What the hell?" the girl- Ace, wasn't it?- said, looking at Steven before she turned to glare at Jack. "Something going on we should know about, Captain?"

"I have to agree with Ace, Captain Harkness," the younger Doctor said, glaring pointedly at Jack. "Given that time itself seems to be fine here, this period of history definitely hasn't been affected by what I expected had caused the problem, but I would appreciate knowing what has caused me so much trouble in accessing this past week of Earth's history… to say nothing of what you're intending to do with that boy."

For a moment, as Jack looked at the Doctor- a Doctor who had yet to witness some of the sights that would have such an impact on his future self; hell, given his lack of reaction to the idea that the Master and the Daleks were still around, the guy probably came from an era before the Time War-, the thought crossed his mind that he could just lie and get him out of here…

But then he looked back at Steven, now standing in the middle of the room, looking in confusion at his 'Uncle' Jack, and knew that he had no choice; if he wanted to save Steven, he had to give this Doctor a chance to help.

"An alien race we know only as the 456 wants to take ten percent of Earth's children and use them as drugs or they'll destroy us," he said briefly.

"What?" Ace said, looking incredulously at Jack. "Drugs? They want to use kids as drugs? How the hell's that work?"

"Something about the chemicals they emit; I'm not exactly clear on the 'how' of it all…" Jack said, before he turned back to look at the Doctor. "The point is, the government's prepared to hand over the kids because the alternative is to be pretty much totally destroyed by the 456, but we've managed to figure out a means of stopping them by broadcasting a reconstitution wave on a frequency that can hurt them based on something they used earlier; the only catch is…"

He swallowed, already knowing as he said it that this statement could never meet with the Doctor's 'approval', before he nodded resolutely as he looked at the man before him. "The only way to transmit that signal is to use a child as the focus point, and Steven over there's the only child near enough for us to use in the time we've got."

For a moment, the Doctor simply stared at him in silence- Jack wasn't sure how to react to that; the complete lack of response to that statement was almost more unnerving than anything else the Doctor could have done-, before he walked around Jack to study the laptop before him, nodding reflectively as he took in the information displayed on the screen before he looked over at Jack.

"I have a plan," he said simply, before he turned to look at Ace. "Ace, what I am about to do is risky, but you mustn't interfere; if you interrupt what I'm about to attempt, it could be very dangerous."

"How dangerous?" Ace asked, looking uncertainly at the Doctor.

"It could fry my mind if something goes wrong," the Doctor said simply.

"What?" Dekker said, speaking for the first time as he looked at the Doctor sceptically. "You can't be thinking of doing what it sounds like; this needs a child if it's going to work-"

"If you were just using a human mind, you would require a child," the Doctor corrected, turning to glare pointedly at Dekker. "However, I am not human; given your evident knowledge of alien activity on Earth, I assume you are aware of my files with UNIT?"

"Well… vaguely; I was always more focused on learning about the 456, the UN tend to keep UNIT files to themselves…" Dekker replied, looking at the Doctor with an unusual mixture of uncertainty and indignity on his face. "But I don't care who you are, you can't just-"

"I was mastering the fine details of telepathic shielding, reception and transmission at an age when you- relatively speaking when comparing your lifespan to my own- were still trying to get your head around Newton's Third Law; I assure you, I can do this," the Doctor said.

"Hold on a minute; are you saying-?" Ace asked as she stepped forward, looking urgently at the Doctor.

"I'm going to help Steven over there transmit this signal?" the Doctor finished- Jack almost couldn't believe how quickly he'd come to consider this little guy before him the Doctor; even with the Doctor he'd met during the trip to Utopia he had the advantage of having seen the guy from recordings of the destruction of Canary Wharf-, nodding grimly at Ace. "Yes, which is why you can't interrupt; any distraction to my concentration could knock my brainwaves out of sync and have dire consequences on Steven or myself."

"You can't do this," Jack said, stepping forward to stand in front of the Doctor even as he began to walk towards Steven, who was looking at the sight before him in confusion; no matter how much Jack wanted to believe that this Doctor could do what he said, his old Time Agent training rebelled against the idea of putting someone in this kind of danger when he already knew them in their future. "You've already confirmed that I know you in the future; if this goes wrong-"

"Captain Harkness," the Doctor said- for the first time Jack was surprised to register a slightly Scottish accent in this Doctor's voice; under other circumstances it might have sounded amusing, but right now it actually managed to be rather intimidating-, his voice low as he glared at Jack, his grey eyes briefly flicking in Ace's direction as she stood uncertainly by the TARDIS before his gaze returned to Jack's, "I only recently witnessed the death of that young woman there, and she is only alive now due to the actions of a madman who saw the world as his own personal chemistry and tried to meddle with time to an unfathomable degree; if there is any way I can save this young boy's life, I must take it."

Staring back at the cold certainty in the eyes of the Doctor before him, Jack could only nod, all thoughts of what he might have said to stop the Doctor pushed aside at the simple intensity of the gaze of the short man before him.

"Good," the Doctor said, as he stepped back from Jack with a brief smile. "Let's get on with this, shall we?"

As Captain Harkness hurried back over to the desk with the laptop on it, the various soldiers in the room continuing to look at him with a certain scepticism- not that the Doctor could blame them; he had to admit that his current body wasn't the most physically imposing he'd ever possessed-, the Doctor walked over towards the young boy standing in the middle of the room, wishing he was as confident as he'd sounded.

In theory, the principle was straightforward enough- once he'd made physical contact with Steven he should be able to 'modify' his brainwaves to 'sync up' with Steven's well enough that he essentially turned himself into a secondary transmitter, allowing him and Steven to share the brunt of the signal that Captain Harkness was about to transmit and thus lessen the damage that either of them would have sustained on their own-, but in practise there was always the risk that he'd make a mistake and forget to adjust the division of the signal so that he took the brunt of it- he knew for a fact that his brain was more 'durable' than a human's-, to say nothing of the risks if he didn't modulate his brainwaves in precisely the right manner…

"Steven?" the Doctor said, smiling slightly as he crouched down in front of the boy, pushing all thoughts of the potential risks aside as the shaken-looking child turned slightly tear-stained eyes to look at him. "I'm the Doctor; I'm a friend of… Captain Harkness over there-"

"Uncle Jack?" Steven said, the fear fading slightly from his face as he looked at the Doctor with a renewed interest. "You know Uncle Jack?"

"Yes… yes, I do," the Doctor replied, already making a mental note to ask Captain Harkness about his real connection to this boy- what he'd sensed when he looked at the man definitely didn't seem normal, but it was hard to identify precisely; whatever had changed him was now so much a part of the Captain it was difficult to register to an outsider- before he left; if he was going to have to 'edit' his memory of this whole mess to stop himself recognising Captain Harkness when he really met him for the first time, he might as well make sure he had something worth erasing. "I need you to help me right now; I need you to focus on me. You'll be experiencing a bit of a headache soon- we need your help with something and it's going to make you feel a bit sore-, but you're not to worry about that; just look at me, no matter what else happens, and you'll be fine. Understand? Simply look at me, and you'll be fine…"

As Steven nodded, the Doctor placed his hands on either side of the boy's head, hoping that this strategy would work; this hadn't exactly been on his list of things to do today…

Then again, he hadn't exactly expected things to be easy when he found that an entire week in Earth's history was suddenly inaccessible; he'd just assumed at the time that it was caused by the damage George Limb had inflicted upon reality rather than something else.

Nevertheless, after all the effort he'd put into figuring out a means of bypassing the block to find out what was happening in that missing week- Ace's suggestion about finding a 'back door' had really proven surprisingly successful; by materialising a couple of days after the 'missing' week and then travelling backwards in time after disabling the spatial circuits to prevent the TARDIS from leaving Earth, he'd managed to essentially 'slip underneath' the block-, he wasn't going to leave Captain Harkness to carry out this plan if there was a chance he could help…

The sound of a keyboard being used forced the Doctor's mind back on track; focusing on Steven as the boy stood before him, the Doctor lowered his usual psychic barriers, opening himself up to the mind that now burned between his hands, Steven's innocent confusion and fear at the situation he now found himself in rapidly spreading through the Doctor's own mind, the Doctor's own thoughts pushed momentarily aside as Steven's innocence filled his own (The part of him that was still him was briefly reminded of the time his third self had 'taken over' for his sixth during that incident with Iam and the Rani, but the rest forced that aside in favour of the current situation), his own brainwaves and mental patterns replacing and supplanting the Doctor's own…

Then the signal was transmitted, and there was no more room for thought. Only the Doctor's Time Lord mind- no matter how much he might be 'tweaking' his brainwaves to allow him to aid Steven in sending this signal, he couldn't change what he was- allowed him to be aware of what was happening, as he and Steven suddenly found themselves aware on some level that was simultaneously above and below normal human thought of every other child on Earth, sending out an 'instruction' that every child would be compelled to obey completely without ever being aware of the full details of the 'order'…

The sheer scale of the power that they were being asked to channel…

The Doctor was vaguely sure that he could even sense his past personalities stirring in his mind to provide him with the support he needed, preserving and maintaining his mind as he opened himself to the signal Captain Harkness was sending to them beyond what Steven was capable of achieving, taking the worst of the damage this signal would cause onto himself while desperately keeping Steven's mind safe, the young boy confused at what was happening to him even underneath his simple belief that his Uncle Jack would stop it, his Uncle Jack would keep him safe, his Uncle Jack wouldn't hurt him…

The signal suddenly terminated, leaving the Doctor only with the disconcerting sense that he'd lost track of the time- as a Time Lord he should always be aware of the passage of time-, before he fell to the ground, his brain disorientated by what it had just gone through.

As the Doctor lay on the ground, he only vaguely registered the pain in his mind as his synapses worked to repair the damage caused by the last few moments of psychic activity he'd put himself through; while it definitely felt like he wouldn't be remembering this little experience any time soon- that burst of energy had seriously knocked his brain cells about a bit; he had a feeling anything from the last few hours would be hard to recollect even in a best-case scenario once this was over-, there was still the issue of getting out of here before he felt the need to ask further question…

"Ace…" he muttered, relieved when his companion appeared above him, her face clearly visible even through his rapidly-blurring vision. "Get me… to the TARDIS… have to leave… mustn't remember…"

"For when you meet that guy in your future?" Ace asked, smiling slightly uncertainly at him as she jerked her head at where Captain Harkness stood silently behind the nearby desk, watching the sight before him.

"Yes…" the Doctor responded, nodding weakly at her. "Don't remind me… about him… after…"

With that last gasped word, the Doctor slumped into unconsciousness, his last impression of the world around him being the sound of footsteps running towards his location…

"Steven?" Alice said, barely aware of the unconscious man lying in front of her son as her little boy turned to look at her, dazed and confused, but alive, somehow- despite what that 'Dekker' man had implied would happen to him- gloriously alive

"M… Mum?" Steven said, blinking rapidly as though trying to adjust to a bright light, one hand going to his head as he swayed slightly. "My head hurts…"

With that, Steven suddenly closed his eyes and fell backwards, only to be caught by the girl in the bomber jacket before he hit the ground.

"He's fine," the girl said, looking reassuringly up at Alice before Alice could ask the question she'd been about to say. "Probably just a bit woozy from having to send that signal; no matter what the Professor did to help him, something like that's got to hurt."

"Of… of course," Alice said, nodding briefly at the young woman before she picked up Steven's still (but breathing; he was definitely breathing) body and wrapped it in her arms, tears trickling down her cheeks as she held him in her arms…

The sound of a door opening prompted her to look up just in time to see her father walk out of the building, shrugging on his coat as he walked out into the corridor that Steven had so recently fled down. For a moment, Alice thought about going after him, but stopped herself; it wouldn't-

"What is he to you?"

"What?" Alice said, turning to look in confusion at the young woman.

"What's your link to the Captain there?" the girl said, her tone displaying nothing but simple curiosity. "Brother, cousin, friend…?"

"He's… he's my father," Alice replied simply; given the current location, it didn't seem to Alice like there was any real point in lying about her connection to Captain Jack Harkness.

The girl blinked, evidently surprised at the statement (Not that Alice could blame her; looking older than her father was something she didn't think she'd ever get used to, and she could barely imagine how the girl before her would react to it).

"Huh," she said, before shrugging it off and looking at her with renewed intensity. "Then you've got to go after him and let him know it's OK."

"But-" Alice began.

"He did something unbelievably terrible to you and the fact that it worked out for the best doesn't change the fact that it hurt you a lot when he did it?" the girl said, looking at Alice with a slight smile. "Been there, done that, got the T-shirt; that sod over there-" she jerked a thumb at the short man with the umbrella and the straw hat, "-is basically the closest thing I've ever had to a real dad- although I'd never tell him that; he's not that great at the whole 'talking about his feelings' thing-, and he once said that I was basically nothing more than an emotional cripple and a pawn in everyone's games to be chucked aside like a used hanky- to say nothing of when he dragged me back to a place I still have nightmares about just to satisfy his own curiosity-… but in the end, I always forgave him."

Noting Alice's sceptical expression, the girl smiled. "Whatever he's done… like I said, he's still basically my dad, and in the end, he always did it for the right reasons- bit complicated to explain why he did it, of course; it's a long story involving mutated vampires and obsessed alien encyclopaedia writers-, not cause he wanted to. Your dad may have been about to do something terrible before the Professor showed up, but he definitely didn't want to do it; he just didn't have any other choice.

For a moment, Alice sat in silence, looking between the girl before her and the son she still held in her arms, going over what she'd just been told, before she shot the girl a brief smile before turning to look at that 'Johnson' woman she'd spoken to earlier.

"Could you… keep an eye on him?" she asked, indicating Steven (A part of her couldn't believe she was asking a woman who'd been willing to 'sacrifice' her son to look after him, but the relieved expression on her face when she'd confirmed that Steven was breathing helped reassure Alice on that front). "I've… I've got to…"

No sooner had Johnson nodded in response, Alice was on her feet and hurrying after her father, only partly registering the girl opposite her calling for help from the other soldiers to get the 'Professor'- as the short man seemed to be called- into the blue box that had somehow appeared in the room since Alice had first seen it.

As much as she might have liked to talk to the girl, she had to talk to her father right now; the girl and her friend could wait until she got back.

Jack never bothered to call the Doctor up and ask if he remembered what had happened during those last difficult moments of the struggle against the 456; after the younger Doctor had helped Steven transmit that signal- Jack hadn't even managed to say goodbye to the guy; when he and Alice came back to the room the Doctor and Ace had returned to the TARDIS and vanished-, Jack had just been grateful that the guy had had any kind of mind left, and didn't see any point in bothering his friend about something that had clearly turned out fine, given that the Doctor was evidently still around.

Besides… as he sat in a park one day a few months later, waiting for UNIT to finish the reconstruction of the Hub, sipping at a few cups of tea with Ianto's sister and brother-in-law- it wasn't as good as the stuff her brother had made but it was still pretty good-, watching as Steven played football with Rhys, David and Mica, Gwen and Alice watching from another nearby bench as they shared various pregnancy-related stories…

In the end, what the Doctor did or didn't remember about his involvement in the defeat of the 456 didn't matter; all that mattered was that he'd helped to save the day once again.

Gwen might have wondered why the Doctor hadn't come earlier if he could, but even without that 'block' the Doctor had mentioned surrounded those dates- evidently the 456's attempt to prevent the Doctor getting involved in their attempted 'deal' with Earth-, Jack had told Gwen that he had a feeling the Doctor wouldn't have shown up anyway.

"He's not here to constantly shield us from the universe," he'd told Gwen in response to her question, during a quiet period as the rest of their group prepared for lunch. "He's here to help us learn how to handle ourselves on our own, by standing up to the things that we couldn't manage alone until we're ready to do so. The human race might have failed to effectively rally ourselves against the 456 at first, but in the end… when the time came to take action or give in without a fight… we could have stopped them at the end even if he hadn't been there."

When Gwen asked why Jack had always made it clear how grateful he was for the Doctor's presence if they could have stopped the 456 without him, Jack had simply smiled and indicated where Steven was currently trying to get past Mica to reach the goal, and Gwen had understood.

Sometimes, when the Doctor showed up, he wasn't just there to save mankind; sometimes, he was there just to save a family, or a man… or, in this case, to save a boy with blond hair whose only crime was to be the grandson of the man who couldn't die, in the wrong place at the wrong time.

The scale of what he saved was never important; all that mattered was that, when it counted, the Doctor always managed to make a difference just by being there.

He might not have saved the world with his presence on this occasion, but he'd saved what he could of Jack's world.

As far as Jack was concerned, no matter how much he might miss Ianto, Steven's survival was far more than he could have ever asked for in those last desperate moments, and was another thing he'd always be grateful to the Doctor for.

AN 2: For those unaware of the classical series, the Doctor here is the Doctor's seventh incarnation- the one two bodies before Christopher Eccleston's Doctor- and his companion at the time of this story is Dorothy 'Ace' McShane, a young girl with a penchant for explosives. Timeline-wise, the two of them have just experienced the events of the novel "Loving the Alien", where this old man called George Limb, trying to avert a future he'd witnessed where he became a Cyberman, created multiple alternate timelines with the use of a stolen Cyberman time machine- even killing Ace to lure the Doctor in to question him about how to use the machine properly-, culminating in Limb committing suicide after he finally accepted that he couldn't escape his fate, Ace being restored to life as the multiple timelines created by Limb's actions 'merged' with the main timeline after his death (This accounts for their presence in this story; the Doctor was making sure that Earth's timeline had repaired itself after the damage Limb had done to it, and, curious about the week that had been 'blocked' by the 456- based on information they'd acquired from scanning Earth's databanks they'd worked out how to generate a signal that would have prevented the TARDIS from materialising directly in that time frame- had entered that era from 'behind'- materialising at some point after the week ended and subsequently sending the ship back in time without moving anywhere in space- to figure out what was happening then)

AN 3: The 'incident with Iam and the Rani' mentioned refers to a time when the Sixth Doctor was trapped on a duplicate version of Ancient Egypt and forced to fight against gladiators; lacking confidence in his own combat expertise, the Doctor was able to use the conditions on that alternate Earth to allow his third incarnation's personality to take control, much like the Doctor here essentially allowed Steven's mind to 'overwhelm' his own; the incidents that Ace referred to where she was 'used' by the Doctor occurred in "The Curse of Fenric" and "Ghost Light" respectively

AN 4: In case anyone's wondering why I did this story with the Seventh Doctor rather than the Tenth, I thought that bringing the Tenth into these events was too predictable and wanted to try something different; given the Seventh's telepathic abilities in the series- he was known to hypnotise some people to do what he wanted when the situation called for it, and once knocked a man out simply by pressing his finger to the man's forehead-, coupled with the fact that he had been known to use those close to him when the situation called for it- much like Jack had to use Steven here- he seemed the logical choice for a past Doctor to deal with a situation like this.