Sam was now convinced that the Doctor must have been mistaken about the watch. He'd been through all the pockets, but he hadn't managed to come up with any sort of timepiece. He wasn't waiting long, however, before he heard the chilling sound of the Doctor's TARDIS materializing a few feet away from him, just slightly to the left of where the ship had been parked before.

A minute or so later, the Doctor stuck his head out the door and grinned at Sam. "Well?" he asked. "What's my time?"

"Perhaps ten minutes," Sam offered.

The Doctor frowned. "Really? I was aiming for two. Nice number, two. Prime, even, positive—"

"It was longer than two minutes," Sam interrupted. "But, Doctor, did it work?"

"Well, of course it worked! What do you take me for?" the Doctor asked, indignant. "Do you think I'm going to go off to do something and come back without having done it?" He eyed the handful of objects at Sam's feet. Nothing unusual, even for him—psychic paper, brainy specs, sonic screwdriver, yo-yo, water pistol, clockwork mouse, bag of jelly babies…. "You've been through all my pockets, I see."

"You didn't have a watch," Sam informed him.

"Odd. Maybe it's in the other suit. Or my coat. Or maybe you didn't just dig deep enough. You didn't find my stethoscope, even." The Doctor nodded to the pile. "But put that back, will you?"

"Dig deep enough?" Sam repeated. "I only found a handful of things in there!"

"Perhaps, but you clearly didn't rummage around. You just scooped out whatever was on top. Do you think I'd go around with only that in my pockets?"

"But—"

"Look here, see?" The Doctor pulled a stethoscope out of his own pocket. It was exactly where he thought it would be. "Me, I know what I'm looking for." He tucked it back in place. "They're bigger on the inside, my pockets, just like the TARDIS. Excellent when everyone thinks I'm not carrying anything at all. Especially when people try to search me and do precisely what you did. Though, if I need the time, I will allow things to shift so that they're digging through for quite a while, trying to unearth everything. Not the best option when they're testy, though. They tend not to appreciate it. Seem to think it's my fault, all the work they go through when searching me."

Sam was quiet for a moment. "If the parallels are spliced, and I've done what I came to do, why am I not leaping?"

"I expect," the Doctor replied as Sam pocketed the sonic screwdriver, "it's because things aren't quite finished yet."

"It's because of your other self, isn't it? And the fact that I've caused him to splinter."

"It's not your fault."

"How can we fix this, then? He told me once the parallels were spliced, the splintering would stop. I should be leaping. And because I'm not, something went wrong, which means I'm not going to leap out!"

"Sam," the Doctor began, "listen to me. I read the report of the time you leaped into Bingo. That time, it was different. I don't know why you didn't leap immediately after Bingo accomplished his task, but I can guess. It was for Al. You knew how much Al needed to see Lisa alive again and free from scorn, didn't you? Oh, some people might say it's just so that you had definite confirmation that it did work, that Bingo did stop Marcie's unintentional murder, but I don't think so."

Sam couldn't remember enough of those details to argue, even though he suspected the Doctor was merely trying to make him feel better.

The Doctor sighed. "Bit different this time, though, like I said. While we could assume that your leaping out will leap me back into myself and my other self back into his own self, sort of like what would have happened with Bingo, I don't know if I'd want to risk it. The splicing may have stopped the splintering, but some splinters are exposed now, and they can catch and tear. We'd be better off to reassert the original conditions, landing me back in your Waiting Room." He grinned. "No alarms bells to herald my presence now, though. Found that. Tweaked it. Which I suppose they've noticed, since it won't have gone off when they switched us. Still. It's the safest option—which is a good reason to explain why you haven't leaped yet."

"But what about the other Doctor?" Sam asked, still not quite sure if he could be mollified by the Doctor's easy words. "He told me splicing the parallels wouldn't reverse the splintering."

"Well, it can't. The splintering was initiated when you leaped into me, and we can't change that. So the splicing'll just stop it. Make sure it doesn't get any worse. Well, not at the same rate, anyway."

"What?" Sam stared at him. "What do you mean, not at the same rate?"

"There's a chance," the Doctor said slowly, "that, if the splintering has gone too far, the binding effects of the spliced parallels won't last. It's like…." The Doctor fished around for an analogy, recalling conversations he'd had with humans over the years, and finally settled on what he considered a suitable comparison that Sam would understand. "It's like when you get a stone chip in the windscreen of your car. Before you know it, you've got a condensed network of spiderweb cracks, all concentrated in one little spot. You don't want it to spread, and sometimes you can stop it, but all it takes is one crack to escape. Sometimes you can't stop that crack. Sometimes it keeps spreading, splitting off and getting bigger, running from one end clear to the other, and nothing you do can stop it, no matter how hard you try."

"But he said he'd shatter if he travelled in the Time Vortex while he was splintering. If we can't stop it, he'll be stuck where he is!"

"Sam." The Doctor looked solemn. "If his timeline were still cracking, he wouldn't be able to withstand the pressure of the Vortex."

Something inside Sam's chest tightened. They were too late. The Doctor was as good as saying they were too late, wasn't he? The splintering might not be getting worse, but just because it hadn't been bad enough to prevent the Doctor from splicing the parallels, it didn't mean that the damage was mild enough on an individual level.

A slow grin began to spread across the Doctor's face, belying his previous tone of voice and giving Sam a spark of hope. "But! I've been giving this some thought. And when you leaped into me, you left a bit of yourself behind, and I hope you don't mind, but I had to use it. You humans are brilliant, and I'm terribly clever, but sometimes I need one of you lot to point out the little, human things that I miss. So…I took advantage of the situation. And…there's a chance that I can mend him. Well, to a point. And I won't even need all the king's horses or all the king's men." He let out a breath through his teeth. "If I play my cards right, I can use some of the energy from my next regeneration to reverberate back and heal the wound in my timeline. I'll still have a nasty bit of scar tissue, but it should put things back to the way they should be."

"Your—? What?"

"Hm? Oh, my regeneration. Not exactly looking forward to it, but I reckon I've got a few years in this body yet, wouldn't you say? Well, unless I do something stupid like trip over a rock." He frowned. "You know probabilities, Sam. What are the odds that, out of eleven chances, my next hair colour will be ginger if I've never been ginger before?" Seeing Sam's expression, he shook his head. "Never mind. Look, when I'm dying, my body will regenerate. I'll change. Completely. All I'll have left of this me are my memories." He looked down at himself. "And a couple more ill-fitting suits."

He was trying to lighten the mood now. Sam could recognize the tactic for what it was.

"Thing is," the Doctor continued, "that process takes a lot of energy, but it creates a fair bit, too. If I can harness that energy and direct it back, then once I've regenerated, I'll have sealed all those cracks in my timeline, and I shouldn't be any worse for the wear. Theoretically. Might be a bit more of a, well, explosive regeneration than I've had in the past, though I suppose it would ultimately depend on what triggers it, but…." The Doctor trailed off, tugging his ear absently. "Not too high a price, is it? I'd be able to repair any damage. And who knows? I might want a change then. I do every once in a while. I did after my seventh regeneration and my eighth. Though I expect the latter was because—" He broke off, instead sucking in a quick breath. "But now's not the time to be discussing either my physiological or personality quirks, so let's get to it, shall we?"

"Get to what, exactly?" Sam asked warily. As much as he was tempted to ask more questions of the Doctor, just to learn more about him, he thought he'd better not press his luck. Even if he didn't get another chance to ask questions—and at the rate things had been going, he wouldn't be surprised if he didn't, even if he would be disappointed—he knew better than to dig for any additional information now. Time was short if the other Doctor was still splintering, spliced parallels or not, and the Doctor had other things on his mind.

"Well, I expect you've told Martha a bit of what's going on now, yes? So, she'll understand when you go to say goodbye. Have a bit of a chat if you like. But you can tell her that things are nearly sorted, and it shouldn't be long. I'm going to pop back over to the Project and fix up my counterpart as best I can and then one of us will nip back here to tell you how things went. Give you a chance to prepare for your leap, so to speak. Besides, I think he said you'd probably want to talk to him, so we'll give you that chance. And then it's back to business as usual, eh?" He grinned at Sam. "I'm sure I would've promised you that you'd leap, didn't I? And I like to keep my promises."

"You did," Sam admitted.

"There we are, then! Look sharp, Sam. It's not the end of the world. Not anymore." The Doctor flashed another bright grin at Sam before pushing open the door of the TARDIS—he'd never properly closed it, Sam realized—and disappearing inside.

As the ship groaned to life, Sam sighed and headed back to the other TARDIS. He had to wonder if, the last time he'd encountered the Doctor, he'd been more harm than help. He certainly seemed to be that this time.

"Al have any news?" Martha asked, knowing by the way the figure entered the TARDIS that it was Sam and not the Doctor.

"Apparently, there's a short delay before I can leap," Sam explained, "but it shouldn't be too long."

Martha's look became quizzical. "But I thought there was all that business with the parallels? I mean, I never could track down the right library. I found another one, full to the brim with mysteries, if you'd believe it, but nothing useful."

"Al had been talking to the Doctor at the Project," Sam explained, "and he's worked out a way to sort that. He spliced the parallels together. That wasn't what I leaped in to do."

Martha refrained from asking the obvious question, feeling that Sam would have told her if he could have. "You're good at what you do," she said instead. "Blending in, I mean."

"I've had to think on my feet a lot," Sam pointed out. He leaned against the railing and looked up. "I wish I could just question the Doctor about all this," he told her wistfully. "Even if he didn't tell me everything, it would be fascinating to hear."

Martha snorted. "It'd be hard to tell if he didn't tell you everything. You don't even have to ask him a question before he talks your ear off." She fell silent for a moment. "You look better now. I mean, even last time, you still looked a bit green around the gills, even if it wasn't as bad as before."

Sam stared at her for a moment, swallowing nervously. "Yes, well. Feel better, too."

"Temporal feedback passed, then?" she continued, wondering why he looked so uneasy.

"Ah…yes. Once the splicing was finished."

"But how could the Doctor splice the parallels if he's back in 1999?" Martha asked sceptically. "Like I said before—like you said before—it's not exactly cutting edge technology compared to this."

"Well, the Doctor's brilliant," Sam pointed out, a nervous smile on his face. "I'm sure he figured something out." Martha frowned at him, so Sam continued, "He said he'd been there before, so perhaps he'd left something that he could use."

"Really?" Martha blinked in surprise. "You'd think he'd mention the fact that humans had discovered time travel before the 21st century."

"Well, as you can tell, it's not without its flaws," Sam reminded her. "I mean, I don't know if I'm ever going to get back home."

"I know. You told me. Remember?"

Sam had looked like he'd relaxed again before, but now he looked alarmed. He masked that quickly, however, instead saying, "Yes, but…. I just have to hope."

"Don't lose it," Martha said, putting a hand on his arm. "Too many people lose hope, thinking that what they're hoping for is impossible." She grinned at him. "And if there's one thing I learned in all my travels with the Doctor, it's that nothing's impossible, even if he thinks it is."

Sam smiled at her. "I hope the Doctor appreciates you, Martha Jones." He tapped her nose, adding, "Because you must be one in a million."

She laughed, swatting his hand away. "And Sam Beckett isn't, when he travels through time, righting wrongs?" They stood in silence for a moment, leaning back, looking up at the TARDIS's impossible interior, but it was a comfortable silence.

"I'm glad I met you," Martha said. "I mean, travelling with the Doctor— Life gets crazy. And this is crazy, too, meeting up with another time traveller, but it's a good kind of crazy, you know?"

"I think I do."

The silence continued for a while, but Martha was again the one to break it. "If you haven't got long, then we should at least make the best of the time we have. Even if you can't take a trip in the TARDIS, I can at least show you around part of it. You won't believe the wardrobe room. It makes the kitchen look like a cupboard!"

"Wouldn't it be called a galley?" Sam asked, looking at her. "This is a ship, after all."

Martha smiled sheepishly. "Maybe. I've never asked. But the Doctor hasn't corrected me so far, so either he's used to it, or it doesn't matter, or something. But, come on. I may not be the best tour guide, but I can try to answer your questions."

Sam grinned at her. "Brilliant." He patted a coral support. "What's this made out of?"

Martha's smile faded. "Um…scratch that. I don't know." She thought for a moment, and finally replied, "Actually, I'm not sure if the TARDIS was made. Not manufactured, anyway. I mean, I wasn't kidding before when I talked about shifting rooms. The Doctor's always going on about her being sentient…." She trailed off, realizing what she'd said. "And calling it a 'she'. Sorry. Guess I'm picking up on that habit."

"Ships often are called 'she'," Sam pointed out with yet another one of his gentle smiles. "But what else were you going to say?"

"Honestly? I think that one time, when the Doctor was babbling on…." Martha stopped, thinking what she was about to say was absolutely absurd. But then, she'd mentioned something like it before, or at least implied it, back before she'd known that Sam was Sam and not the Doctor. "I think he said she was grown."

Sam reached out to touch the strut again. He closed his eyes and listened to the living ship. "You know, you might be right. Oh, that's brilliant, isn't it?" A grin—the Doctor's grin—split his face. "Martha Jones, you may not think you're going to be an ideal tour guide, but I think you're the perfect one to show me the sights."

"We can swap stories," Martha offered. "I'll tell you about travelling with the Doctor, and you can tell me what you remember about your leaps, since I won't be able to tell you much about the TARDIS herself."

The look on Sam's face told her the idea appealed to him; familiar enthusiasm was etched into every line. "I may not have been much help on this leap," he said—more to himself than her, she realized— "but I think this will make it worthwhile. I just hope I'll remember this after I leap."

Martha, who found herself hoping much the same, if only so she might one day have someone to talk to after she'd stopped travelling with the Doctor, whenever that day came, took Sam's hand and led him into the depths of the TARDIS, telling herself that he'd make it home, some day. He had to. Didn't he?