Tiffany looked at the round device on her wrist again. "Oh, damn." she said mildly. "I've got to be going if I want to make it back to the TARDIS before morning."

"You're going back?" Adric said, still blushing over their awkward handshake. He stuffed his right hand into his pocket with the air of someone putting a paper bag over their head. "What for?"

"To bring it back here, of course. Can't very well be lugging great heaps of machinery over that distance."

"But it won't run." he objected. "It's as good as ruined."

"Actually it's not." Was that a blush he saw rising into her cheeks? "I purposely threw off the coordinates and told you it wouldn't run because I had to make sure you didn't have a way to escape. I couldn't very well leave it lying about where you could hop in at any moment and be gone in the blink of an eye, now could I?"

"So you dragged me across the desert for no reason?"

"Do you ever listen to anything I say?" Tiffany demanded, exasperated. "I had to make sure you couldn't escape."

"But you didn't have to drag me through all those spines!"

"Yes, actually, I did. Otherwise you would have just run back to the TARDIS and flown off. And it got you to take the narcotic, which saved you a lot of pain and me a lot of whining."

"So it was all an elaborate trick."

"And not particularly elaborate, at that. Now if you'll excuse me, I've got to be going. Be back in . . . oh, probably five minutes."

"But you said you wanted to reach the TARDIS by—"

"It's a time-machine, you nincompoop." she scolded, tugging on a strand of his black hair. "Bye! Oh, and I wouldn't recommend trying to escape while I'm gone. The Master will be very, very angry if you try, and he's not completely wedded to the idea of keeping you alive, if you get my meaning. Toodle-oo!"

"But, if you go and get the TARDIS and bring it back to five minutes from now, it won't be there when you go to get it."

"What?" Tiffany said, turning around. She was almost at the door, but was so puzzled by Adric's statement that she had to stop a moment and think about it.

"Well, if you go and get it by the morning, and then bring it back here five minutes from now, it won't be out there in the desert when you go to get it, it'll be here."

"Yes, it will be here, but it will also be out in the desert. It's a fifth-dimension craft, Adric. It really can be in two places at once."

"But—"

"It's time-travel. Do you really expect it to make sense? It's based entirely in quantum physics. Its very existence is nonsensical."

"But I don't see how—"

"Would you shut up? My God, you can't make the world make sense just by arguing about it. Reality isn't a calculus problem."

"Quantum physics is based entirely in maths."

"Oh, maths. You see, Adric, the trouble with maths is that they all take place in some fictitious universe where everything is always absolutely perfect. They don't really apply, see?"

"Physics is applied mathematics! It translates directly from calculus!"

"Then why do scientists have a margin of error?"

"Because nothing is perf— . . . oh."

"You see? I'm always right, so you needn't bother arguing about it. Even when I'm wrong, you must never, ever rub it in, because if you do, you'll be sleeping on the couch for the rest of our acquaintance."

"On the what?"

She rolled her eyes. "Oh, never mind. Stay here, and for God's sake don't touch anything. Be back in a few. See if you can stay out of trouble for that long, would you? If you last five minutes it'll be a record, I'm sure. Now, I'm leaving, and if you interrupt me again, I'll put sand in all your food from now until the day you die. Okay?"

"O-okay."

"G'bye, then!" And she strode out the door.

Adric took the opportunity to examine his surroundings more thoroughly. He walked the perimeter of the room slowly, running his hand along the rough-hewn stone of the wall, searching for hidden exits and alcoves, and just generally getting the feel of the place. He kept one eye on the glowing orb in the centre of the room, thinking there was something extremely familiar about it, and entirely unable to place what it was. Once he made it around to the single entrance to the room, his brain was nearly itching with the effort of recollection. Maybe, he thought, if I examine it more closely, it will come back to me.

He crossed the room slowly, hesitantly, expecting Tiffany to come through the door at any moment and scold him for touching things, or thinking about touching things, or looking like he was thinking about touching things. He certainly was thinking about touching the pearlescent orb, but he would never let on that he was; he knew it was a bad idea and he didn't particularly care.

The orb sat on a pedestal of what appeared to be wrought iron, an ugly system of supports that looked like post-modern spiderwebs. These were hammered into the rock beneath, which was in the form of a sawn-off stalagmite, sitting in the centre of the room like some sort of hub for this gigantic hemispherical wheel of a cavern. The ball hummed gently with the mechanical whirr of cooling fans, rather like an old Earth computer thinking seriously about some complex operation. Adric stared into its depths, dark brows furrowed in concentration, the white light of the orb reflecting off his black eyes. Carefully, he reached out one hand and touched the very tip of his finger to the surface of the orb as gently as he possibly could. The mist inside swirled around the point of contact as though investigating, and a few trails of pink and green wound their way up to the surface.

"Biometrics," Adric murmured to himself, finally remembering where he had seen such a thing before. "This is a biometric orb."

"Well spotted." came a voice from behind him. He whipped around and nearly knocked the sphere from its iron pedestal, turning back to catch it when he saw it falling in his peripheral vision. "And here I was, thinking you could go five minutes without fiddling about with anything."

"Tiffany, I—"

"Oh, shut up. Yes, it's biometric." She walked over to stand next to him by the orb, her own eyes catching and reflecting its light. "It's also incredibly fragile and the only one of its kind, so you're lucky you didn't break it. Hello again, by the way. Been a while, hasn't it."

"So you. . . ."

"I went and got the TARDIS and I brought it back here. Waved to myself on the way in. That probably isn't good for the timeline, but it's just so much fun."

"Why is there a biometric orb on Earth one hundred and forty million years before the birth of mankind? Did some other intelligent species inhabit this planet?"

"Intelligent?" Tiffany inquired, raising an eyebrow. "Psh, there's never been intelligent life on Earth."

"If Tegan is anything to judge by." Adric said, before he could stop himself. To his immense surprise, the Master's apprentice laughed.

"I can only imagine what would happen if she heard you say that. You would be up the creek without a paddle, my friend."

The word struck Adric like a physical blow. Friend? He wasn't sure he'd ever had friends. A friend, even. Certainly he'd had an acquaintance who did more than just tolerate his presence. Maybe. Depending on your frame of reference.

"Hello-o, Earth to Adric, come in, Adric! Anyone home?"

He realised that a hand was being waved in front of his face. "Wha—? Oh. Sorry."

"Hypnotised by the shiny orb? Don't worry, it tends to happen to the weak-minded."

"No, I just . . . I was thinking about my friends."

Again, she raised just one eyebrow. "You had friends?"

"No." he replied, looking away into the depths of the orb. "That's what I was thinking about."

He heard an exasperated sigh, and Tiffany put a hand on each of his shoulders, turning him to face her. He was forced to look into her eyes, which always made an embarrassing flush rise to his cheeks. And then, of course, because it was embarrassing, it got worse, until he was red to the tips of his ears.

"Look, Adric. I am only going to say this once, and if you let on at any time that I said it, I will paint your fingernails pink and braid your hair and tie off every single braid with a little pink bow."

"How evil of you." he said, sarcastically, although he could feel his blush spreading downwards across his neck and up across his hairline.

"You have no idea. But listen, really. People find you annoying, and I don't blame them. But that doesn't mean they don't like you. And even if they don't like you— which I wouldn't blame them for, either, I can see how it would happen—"

"Is this supposed to make me feel better?"

"Shut up and let me finish, you ridiculous creature. What I'm trying to say here is this: friends don't have to like you, and they don't have to enjoy being around you. But in essence a friend is someone who looks out for you, who doesn't let you fall behind, who comes looking for you when you've been hurt. A friend is there for you when no one else is. Now tell me this, silly boy: when has Tegan, or Nyssa, or the Doctor ever purposefully left you behind? When have they ever refused to help you? When have they ever not been there for you?"

"You mean like when they abandoned me to die on that freighter?"

"They were going to come back for you, you know." she said quietly, refusing to look away from him. Again he was struck by the fact that she was shorter than he was. He was beginning to learn what the expression 'larger than life' meant in practical terms. "There was a Cyberman aboard the TARDIS and they had to kill it. Once it was dead, the Doctor tried to get to the freighter, only he was a few seconds too late."

"And after that it was too dangerous for Tegan and Nyssa, yes, all right, fine."

"No, not fine. For weeks those two women were harassing the Doctor non-stop to go back and get you. Both of them."

"Tegan? Tegan wanted to go back for me?"

"She was very clear about that, yes. She got into a raging row with the Doctor not too long after. It was worrying, really."

"Wait, how did they kill the Cyberman?"

"Oh. Er. . . ." She looked away.

"He used the badge, didn't he."

"Um, yes. Yes he did. To great effect, I might add."

"Is it broken?"

"Thoroughly."

Adric sighed. "Yes, well. I rather intended for him to use it that way."

"It was just a badge, Adric."

"It was a lot more than that."

"It only meant anything on Alzarius, which is in a completely different universe, may I point out."

"It meant something to me."

"Look at it this way: it was an extremely effective weapon against the Cyberman, saving all three people aboard, and therein served a much greater purpose than it would pinned to your great orange pocket. Besides, it looked rather stupid."

"It was an excellent lock picking tool."

"Always knew you were born a criminal."

"I was not."

"Then why, pray tell, do you know that your badge was an excellent lock pick? How would you know unless you had been picking locks?"

"But I didn't break into places to steal things!"

"No, I imagine that was rather an afterthought. By the way, your left hand has snuck something into your pocket. I don't know what it is, but I would bet money it isn't yours."

Adric's hand clenched on the object in his pocket. It was none of her business what it was, but telling her so would only prompt her to take it out of his pocket and examine it thoroughly.

"Look, why is there a biometric orb in this room?"

"To contact the power source." Tiffany replied, finally removing her hands from Adric's shoulders. "It can be a bit finicky."

Adric was about to ask five questions in rapid-fire succession when the Master strode in through the door.

"Tiffany, get him back to the TARDIS and get to work adapting the circuitry for the transfer. See if you can't use him to speed up the process. We have company."

"Company?" said Adric, before Tiffany could clamp her hand over his mouth. The Master's eyebrows twitched.

"Oh yes. Your dear friend the Doctor has come to throw a spanner into the works."

"Oh, hell." said Tiffany, and dragged Adric off before he even had the chance to ask what a spanner was.