A/N: So, one more Doctor Who/Quantum Leap crossover, at the specific request of Elvaro and the subsequent encouragement of Questfan. I highly recommend reading Patchwork, Splintering, and especially Splicing before reading Cracking, or the story will be more confusing than it is already bound to be (just ask anyone who has read any of my other stories). It follows The Waters of Mars for the Doctor and is before Return for Alia, for whom it has been a few years since Splicing and an undisclosed amount of time since Deliver Us from Evil.

Disclaimer: I don't own these characters, and I make no money from this work of fiction!

The Doctor had known what he'd been facing, back when he'd been up against that fixed point on Mars, back when he'd defied the laws of Time because he couldn't stand seeing any more death. He'd nearly destroyed everything, then. He was very, very fortunate—not to mention very, very humbled—that one human woman had understood the gravity of the situation and had done what he hadn't been able to do, what he should have done, and had saved the timeline by sacrificing herself.

To say that he had overstepped his boundaries would be putting it mildly.

He had sorely needed to be put in his place.

He had been.

But he hadn't known when to stop, and there had been no one there to stop him.

Which meant that he was still dealing with the consequences, the aftermath of his mistake, even if it was not as great as it could have been.

He could have destroyed the entire future, completely shifting it from its proper path—probably irreparably. He could have been facing a complete deterioration of the timeline as he knew it, with the future being shunted along the nearest available path into the most likely parallel world, with any distinct differences being lost immediately. As it was, he was just dealing with cracks.

They were a tad more extensive than he would like to admit to anyone else, now that he had a chance to inspect them a bit closer.

After that business with the timeline splitting into parallels and his subsequent splicing of them, he really had to watch it when something cracked. It gave him a bit of a headache as it was, seeing as he'd nearly splintered, and he, originally, hadn't been the one to do the splicing. That was the work of his other self. But, because his other self had managed to stop the splintering process and patch him up, sealing up the cracks that had threatened to break him apart much in the same way that he had to seal up the cracks in the timeline now, he'd as good as spliced the parallels himself, because, technically, he had done it.

It wasn't like remembering something he'd purposely forgotten. Those memories always seemed to fit, filling in a gap that he hadn't known had been there. But it wasn't like having false memories forcibly implanted, either, because these memories were real, and they were actually his memories. And it wasn't precisely that they didn't fit, although that's not to say that they weren't shoved into place between what he'd originally done. It was more…. Well, he couldn't really say what it was like, not accurately. However much he knew they were his own memories, he also knew that they were products of a changed timeline. He knew them as well as he knew the rest of his memories, but they still had that feeling to them, whenever he recalled them.

Of course, it had been another one of his mistakes that had gotten him into that mess, with the parallels and the splintering. He'd gone and changed something and hadn't tracked the consequences as closely as he generally did. He'd meant well, yes. And as far as he had traced it, initially, nothing had been noticeably wrong. He would have picked up on it later, of course, if he had continued following his timeline as he ought to have, but when it had changed, and he'd started splintering, well, then he'd really noticed that something had gone wrong.

It should have knocked some sense into him. It should have reminded him of everything he'd been preaching. It should have stopped him from doing something so distinctly wrong even when he meant well, meant for it to end better than it had, originally. Happier. But the greater consequences…. He'd ignored those greater consequences, just that once. He had been determined to find another way to set things right. He had been determined to guide the timeline along the proper path. He had been determined to control it, making sure it still ended up where it ought to, without all the pain and loss and suffering. There was far too much of that as it was.

But he'd been wrong.

And he hadn't had the sense to see that. He'd ignored it. He'd gone against his better judgement, against his instincts, against all his learning, even though he'd known, on some level, that he'd face something like that. That he'd make that choice, and choose poorly. He'd caught a glimpse of it when he'd been splintering. It had preyed on him, that glimpse, but he hadn't been able to think straight as it was, and there had been so much other stuff that he could see, all at once. And he'd known even as he'd seen it that he shouldn't look, shouldn't peek, but he hadn't been able to block it out. He'd been horrified, but he'd been resigned to it, just as he'd been resigned to the fact that he was going to splinter, shattering apart, scarring who knew how many timelines in the process.

Even when he hadn't, in the end, he hadn't ever looked back, recalling what he'd seen so that he could prepare for it. He'd shoved it to the back of his mind. He'd refused to look. To look behind him and see ahead…. It would have been terrible to know. But that knowledge would, perhaps, have stopped him from doing what he'd done. But even knowing that he would, eventually, make that mistake, hadn't stopped him from making it. He'd blatantly ignored that warning, that spoiler, along with everything else.

And now the timeline, in a slightly weakened state from his previous notable mistake, despite being spliced, was cracking—because he'd been foolish enough, arrogant enough, to make another terrible mistake, however surrounded with good intentions it had been.

So now, he was back to a bit of temporal patchwork, trying to fix his own mistakes before it was too late.

Trouble was, he'd been at it for a while now.

And the cracks weren't sealing.

Or, rather, they weren't staying sealed.

And he could only patch something so many times before a change became permanent.

But he really shouldn't need to be patching these more than once; twice, if the crack was particularly deep. And most of them weren't. Most of them were still just surface cracks. Easy to fill. At least, normally easy to fill.

If his repairs weren't holding, then it meant that he hadn't found the source of the problem.

Which meant that while he might have been responsible for a few of the cracks, he wasn't responsible for all of them.

Which meant that he had to find out what was and stop it.


Preferably, before everything cracked and crumbled.

"Well, don't you think so?"

Alia blinked, staring at the young man in front of her, trying to get her bearings. "Of course," she agreed, wishing that there were another person here to bear the brunt of the conversation while she sorted out what they were talking about.

"Then why say that Marie ought to break it off?"

Oh. Relationships. Easy enough, then. Alia smiled. "Because Marie can do a lot better than him." She leaned forward to sip her soda from the straw in her glass, keeping her eyes on the man in front of her.

"Brian's top of his class!"

Alia shrugged. "You asked my opinion. That's what it is. There are more things to look for in a man than just brains."

The man gaped at her. "Grace!" he admonished. Alia just smiled. The man still looked flustered. Alia had seen the look enough times to know that he would cast around for some excuse to leave, or change the topic, or otherwise wrap up their current conversation. She left him to it, taking the time to get a better look at him.

He was probably in his mid twenties. Brown hair, brown eyes, glasses, and fairly average-looking overall. He was sitting, so she couldn't gauge his height, but he didn't look particularly gangly. He looked like the sort of person who blended right into the crowd. Nothing special, not on the surface. She vaguely wondered if she had to kill him, or if she was going to get off easy this time and was simply required to ruin his life.

"Maybe we ought to revise again," the man said.

University student, Alia realized. And a geeky one at that. Probably in the top five of his class. And she was clearly a classmate. Alia sighed, hoping that this leap wouldn't be a long one. She never particularly enjoyed staring at books full of things she didn't understand. "Must we?" she asked, rolling her eyes. "It feels like that's all I've been doing lately." A risky statement, perhaps, but her classmate had said again and maybe, meaning he was doubtful as to whether she would agree to what was clearly a repeated action.

She received a crooked smile in response. Right answer, then. "I guess we have, haven't we?"

Silence followed. He was expecting her to say something. Great. She looked at her feet and saw a book bag. Excellent. She snatched it up, saying, "I'll be back in a minute or so. I just want to wash up." She'd spotted the washroom sign in her earlier scans of the café in which they were seated, and now was as good a time as any to find a wallet and some identification to figure out who she was—and what she was studying.

She threw her bag up on the counter with the sinks and began rifling through it. She pulled out a clipboard of notes—whoever she was, she was certainly a messy writer—and a couple of textbooks. Medical textbooks. Great. It wasn't even something she could fake well.

She pulled out an agenda and started flipping through it. Still September, from the looks of it; the leapee was crossing off the days. Already. Not that Alia was about to complain. It told her that today was September 18, 1987. "And you're revising already?" Alia asked in disbelief, not caring that she was talking to herself. "Talk about dedication. You must be a serious student." A bit more rummaging, and her fingers at last closed upon the leapee's wallet. Finally.

She flipped it open. Student card, opposite the California driver's license. "Grace Holloway, is it?" she asked, reading it. "Well, I hope you didn't have any great future plans, because I have the feeling that by the time I'm done, you'll want to drop out of university."

She studied herself in the mirror for a moment, nodded, and picked up her bag and left, not bothering to return to the table where her classmate was waiting for her. Zoey would be along soon, and she didn't need to get into any more conversations where she didn't know what was going on. Until she had more information, she wasn't going to talk to anyone. All she had to do was pretend to be in a rush, and her likelihood of being stopped and questioned would drop. It was always better to act like you had a clear destination in mind. All it took was a bit of practice.

And she'd been doing it for years.

"Where is she, then?" Zoey asked, sounding rather bored. Thames had been at Lothos for a while now, and she clearly knew he had found something. She didn't get as tetchy as she used to when he didn't have the answer immediately. She didn't appreciate what it took for him to get the answers she expected him to have, but at least she didn't demand them immediately.

Especially since it took longer to get the information when they weren't the ones who had sent Alia wherever she had ended up.

"San Francisco," Thames reported. "September 18, 1987. As a university student, a Grace Holloway."

Zoey smiled slightly. "We'll get a chance to check out the frat boys, then. I do love—"

"Med student," Thames cut in. "If Alia plays her role, attending classes to keep tabs on whoever she's watching, she's not going to have a lot of time."

Zoey snorted. "We don't know if she's supposed to be watching anyone, Thames. We don't know why she's there. It's your job to find out." She let out a bit of a huff. "I do hate it when she's thrown off into one of these unprogrammed leaps. It's terribly difficult to get her back on course."

On course. That was a laugh. They were lucky that they had garnered enough control to keep Alia sequestered to a certain type of assignment—assignments which seemed, at least to him, to be easier than they used to be. But, of course, she still slipped off track every once in a while, and he had to spend countless hours pouring over Lothos, trying to sort it out.

He wouldn't be getting a lot of sleep this week.

And he'd probably have to spend the entirety of it listening to Zoey either complain or gloat.

Another glorious week ahead of him, he was sure. If he was lucky, he'd find out that Alia was there to do something particularly gruesome, and then his work would at least all be worthwhile. Those simpler assignments she'd had recently, like home wrecking—it hadn't been very amusing, not for him. It wasn't the sort of thing you could enjoy if you weren't there to watch it unfold.

But he knew better to complain, and that was why he was still alive and kicking now. That had been one lesson a good many people had been too slow to learn. Besides, survival wasn't just knowing when to keep your mouth shut. It involved a certain mindset, and you either had it or you didn't, because if you simply pretended to have it, you'd slip eventually. And he'd taken great pleasure in finding those people, ferreting them out, tracking them down, making sure they paid the consequences of attempting to fool them.

Of course, he'd hardly gotten through his third rouge of the Project staff when Alia had leaped into Connie LaMotta of Oakland, California, in March of '66. Because after that, he'd been researching everything he could about a certain Dr. Samuel Beckett. Zoey was livid about that, and she had every right to be, as far as he was concerned, because she had paid the price. She and Alia both had been punished for letting Dr. Beckett get away. Alia had really needed to pull her socks up after that to prove her worth before they terminated her, cutting her off from the Project completely.

But the whole meeting with Dr. Beckett had struck an unsettling chord in Thames for a very different reason.

It had reminded him, all too strongly, of the last time a scientist had slipped through their grasp.

And the infuriating Dr. John Smith had, on the day of his escape, the day he'd destroyed their retrieval system and wiped most of their records, mentioned another project.

Thames hadn't paid him much attention at the time. It wasn't like the man had made much sense previously, and, on the day in question, he'd just gotten out of at least a week in isolation. Thames hadn't been expecting him to make much sense. Dr. Smith had called them the wrong project, then. And though Thames had questioned him, just in case there was anything to it, Dr. Smith had evaded him. And then he'd gotten away, and they were dealing with that, trying to sort everything out, and Thames had forgotten all about that slip of the good Dr. Smith's, deliberate or otherwise.

Until they had discovered Dr. Samuel Beckett, and his time travel project.

They hadn't realized it immediately. Lothos had been picking up strange fluctuations that they were unable to account for, but they hadn't imagined that anything of this magnitude would turn up. And when it had, well, decisions had been made. Quickly. Only, Alia hadn't carried them out. She'd disobeyed, in spite of the consequences. She'd ignored Zoey, and she'd listened to Sam.

She hadn't ever said why, but Thames had some pretty strong suspicions now. Not that he mentioned them. It wouldn't do to mention them. And it wasn't like they could act on those suspicions anyway. Dr. Smith was long gone, and they hadn't managed to find him. Not in the present, and not in the past. Although Thames had thought they'd been fairly close to it, that time that Alia had encountered Dr. Beckett.

If Dr. Smith had known about Dr. Beckett's project, it certainly explained a lot. It explained how he'd known things about their Project that they'd never told him, or how easily he'd adapted to Lothos, or how he'd managed to put everything together so quickly, or how he'd been able to talk as if he were experienced in this sort of thing. It even explained who had sent him. But it didn't explain why.

There weren't a lot of things that irked him, not now, but Dr. Smith's attitude had been one of them. He'd acted like he'd known what was going to happen. He'd acted like he had years more experience than them, as if he were the parent to children who were intent on playing with something they mustn't touch. He'd acted like they were ignorant fools, as if their power were merely imagined. He'd acted like he'd owned the place, as if he'd engineered everything to happen and was pleased, but not surprised, when it played out exactly like he'd expected it to, exactly like it should.

He had never said why he'd come. He'd only taunted them. At best, he'd said that he thought that he could get something out of it, the action of helping them. But he'd never said what. And he hadn't taken anything with him when he left. He could have. He'd accessed Lothos's memory banks, destroying records galore. They didn't know for certain that he hadn't taken anything with him, true, but if he had just come for information, he could have gotten it a lot quicker than he had. Besides, Thames had been the last person to see him at the Project, before his escape, and the man certainly hadn't acted like he'd taken anything.

Not that his actions had told anyone much of anything, especially since he'd finally snapped. Though, Thames was hesitant, now, to say that it was as simple as that. It wasn't something he could put his finger on, not really. It just…eluded him. And he hated that. He wanted answers, and he really didn't care how he got them. But the only one who could provide those answers was the elusive Dr. Smith himself.

Seeing as Dr. Smith would probably be shot on the spot if he so much as showed his face anywhere near their Project, it didn't particularly surprise Thames that he'd made sure he'd dropped off the map. It also wouldn't surprise him if he didn't get answers, even if they did run across him again, for that very reason.

He just hoped he got a piece of him before there was nothing left.

"I'll have a better shot at figuring out why Alia leaped in there if you go talk to her," Thames informed Zoey sourly.

"Oh, there's no need to be testy," Zoey replied, her tone slightly scolding. But she wore a slight smile, and Thames knew she was expecting to enjoy herself immensely. "Very well. Tell me what you can about this Grace Holloway, and I'll inform Alia how she is to act." Picking up the handlink, Zoey swept out of the room before Thames could answer.

He started plugging information into the handlink, having made sure that the Imaging Chamber was online and functioning and ready to lock onto Alia. Once Zoey started collecting information, it wouldn't take him long to run it by Lothos, and then they'd have a better idea as to why Alia had leaped where she had. Then, all they had to do was run the course of the leap, as if it were a routine thing, and they'd gain a bit more control over Alia again. Easy.

Or so he'd thought.