"Who are you?" The Doctor stares at him. Sam's a little daunted by the attention.

"Harry Sullivan." That's the name of the man he's leaped into.

"No, you're not."

Pretending to be someone else isn't always easy, so Sam's glad to hear the sound of the Imaging Chamber and the squawk of the handlink that tells him Al is back. "Who else would I be?"

"I don't know, that's why I asked. And I'd like to know how you got on my ship." The Doctor turns to face Al, who goes wide-eyed at the attention.

"You can see me?" Al asks.

"Of course, I can." The Doctor sounds hurt at the suggestion.

"Oh, boy." This is clearly going to be one of those leaps. "I'm Sam Beckett." Al looks horrified, but Sam figures he might as well give it a go.

"The playwright?"

Sam shakes his head. "The quantum physicist." Among other things, but that's what counts at the moment.

The Doctor smiles at him, which just unnerves Sam all the more. "The time traveller. You leap from life to life, fixing what once went wrong."

Sam blinks and looks over to Al, who is hitting the handlink. "Who would I tell?" Al says and he has a point.

"So tell me," the Doctor continues, "what are you here for?"

"I don't know." He does, but it's not something you blurt out. It has to be handled delicately. Especially given that Ziggy can't tell them what the Doctor is feeling or give them very reliable odds.

But the Doctor goes around behind Al and reads the handlink over his shoulder. Al is so used to not being seen that he doesn't move away, just frowns at him.

"Sarah Jane's in love with me?" the Doctor says.

Sam gives Al a look. Al shrugs.

"We'll see about that." And with that, the Doctor wrenches open the door and disappears into the ship.

Sam sighs. Everything that could go wrong on this leap has gone wrong. And now he has to fix it.

"How am I supposed to know that aliens can see me?" Al says in his defense.

Al has a point. Until now they hadn't even known aliens existed. "What are the odds in me succeeding now?" Sam asks, sounding as tired as he suddenly feels. He's going to have to do something different and he has no idea what.

Al hits the handlink a few times before he comes up with an answer he looks shocked to read. "One hundred percent."

"What?" Sam can't believe that.

"That's what it says." Al holds the handlink up so Sam can read it for himself and Al's right, it does say one hundred percent.

Wondering where the Doctor went, Sam tiptoes through the door. And there, just around the corner is the Doctor in the corridor. And he's kissing Sarah Jane.

Sam exchanges a smile with Al. This is the easiest leap he's ever had.

"You did just spend all night making sure Scott and Billy didn't commit that robbery."

Sam shook his head. "No, I mean I'm tired of being in other people's lives, of not being able to go home."

Al didn't reply, so after a while Sam opened an eye. Al looked down at him with sympathy and guilt in his expression.

Upon realising he was being observed, Al said, "If there was something I could do..."

But they both knew there wasn't and Sam leaped as he fell asleep.

Al glanced down at the handlink and nodded.

Sam sighed. "Sometimes I wish we had a better chance to talk."

"We will. When you come home."

Al sounded so sure that Sam was still smiling when he leaped. Usually he was the one who was sure everything would work out and Al was the worrier. It was when he thought of his future that their roles reversed. He didn't have much of his own, but Al had enough faith for both of them.

Since that wasn't going to happen she had to build her own. There was plenty of time, in between looking up information for the leaps, hacking into the FBI computers and helping Al Calavicci with the crossword.

When she proudly presented the new computer Tina and Gooshie went into raptures over it and Al beamed, saying how he'd have to tell Sam he was a grandfather.

They ignored her. So Ziggy switched the new computer off. Permanently.