Rimmer stopped in the doorway to the bunk room, aghast at what he saw inside. Lister was sitting on Rimmer's bunk, and Cat was sitting on a bench by the window. Under normal circumstances, Rimmer would've been annoyed, but it wasn't so much where Lister sat as it was what Lister was doing that made these incredibly unusual circumstances.

Lister glanced at Rimmer from behind what looked like a real, thick textbook. "What?"

"You're reading," Rimmer said.

"Yeah," Lister said.

Rimmer struggled to find words. "I didn't know you could read."

"Of course I can," Lister said, turning back to his textbook.

"So," Rimmer said, not sure what to do about this turn of events. "What are you reading?"

Lister held up the book so Rimmer could see the cover. "Principles of Astronavigation."

Somewhere in the back of Rimmer's mind, alarm bells began to go off. "Astronavigation?"

Lister nodded. "Yeah, I'm studying for the test."

"But you never wanted to take that test." Rimmer's voice was a little more high-pitched than it should've been, but otherwise, Rimmer thought he was controlling himself amazingly well.

"I've had my priorities all wrong. I should be thinking about getting ahead," Lister said.

Lister's goals were starting to sound uncomfortably familiar to Rimmer. "You should?"

Lister held up a clipboard on the bed beside him. "Yeah, and I'm making a start. I've got my color-coded study timetable all worked up."

Rimmer's legs threatened to give out beneath him. "You made a timetable?"

"Of course. How else would you study?" Lister said.

"I don't know," Rimmer said. Lister didn't do things like this. Lister wore his socks for six months running and considered it a talent to be able to brush his teeth without a toothbrush; Lister did not make color-coded study timetables.

Rimmer sat down, disturbed by the change in Lister. Maybe now was the time to bring up the matter of the bunks. "Why are you in my bunk?"

"This isn't your bunk. It's my bunk," Lister said, still reading his astronavigation book.

"Since when?" Rimmer asked. He was beginning to get nervous.

Lister rolled his eyes. "It's always been my bunk, Lister."

Rimmer's simulated heart skipped a simulated beat. "What?"

Lister looked at Rimmer dubiously. "Can't you hear me?"

"What did you call me?" Rimmer asked.

"When?" Lister said.

"Just now."

"I called you by your name," Lister said. "It's what I always call you."

Rimmer nodded. "Right. So what is it?"

"What is what?"

"My name."

Lister sighed deeply and shook his head. "Don't be a gimboid."

"You never say gimboid. You say smeghead," Rimmer said.

"What?" Lister said.

"I say gimboid. You say smeghead," Rimmer said, feeling as though he had wandered into another parallel universe.

Lister closed his book. "Let's call the whole thing off. I'm going to the Observation Dome to study."

Once Lister was out of the room, Rimmer began pacing back and forth. What could this mean? Lister had suddenly developed goals nearly identical to Rimmer's, was studying astronavigation like Rimmer, had even started using Rimmer's favorite expressions…oh no. This could not be happening.

"Cat?" Rimmer said.

"Mmm?" Cat said.

Rimmer tried to think of a delicate way to phrase his question. "Did you notice anything…odd about that conversation?"

"Odd how?" Cat said, looking as if someone had caught him trying to eat Lister's mechanical goldfish again.

"Like when Lister called me by his name?" Rimmer said.

"Oh, that kind of odd. Yeah, I noticed that," Cat said, sounding relieved.

Rimmer took a deep breath. "Can you stand a shock?"

Cat stood, making a horrified face. "Don't tell me burlap's come into fashion!"

Sometimes Cat could be so mind-numbingly dull that Rimmer suspected Lister's toenail clippings had a higher IQ. "No, you stupid git. I think Lister's gone space-crazy."

"How can you tell?" Cat asked.

"He's starting to think he's me," Rimmer said.

Cat shrugged. "So?"

Rimmer began to pace again. "Don't you see? This could ruin everything. He's motivated now!" He stopped mid-pace as a truly horrifying thought occurred to him. "What if he passes the exam? He might outrank me! And with another me ordering me around…" He trailed off as he remembered the last time there had been two of him on Red Dwarf. He didn't want to repeat that experience one bit. "I have to stop this."

Cat didn't seem too interested; he had already turned to the mirror and was fixing his hair.

Rimmer raced out of the room. He had to come up with a plan to get Lister back to normal.

Rimmer paced up and down the corridor. After making and discarding hundreds of plans, he had finally come up with one that would work. "Holly, do you still have Lister's personality stored somewhere?"

Holly appeared on a nearby viewscreen. "I think so. Yeah."

"Can you overwrite some of my personality elements with his?" Rimmer asked.

Holly looked apologetic. "Sorry. Didn't catch that last bit. I think I had water in my ear."

It wasn't just Cat. Everyone had the mental capacity of a potato. Rimmer was the only brain on this ship, but he decided not to flaunt his superiority too much. "You're a computer. If you had water in your ear, you'd short out."

Holly nodded. "It's a good job I didn't know that before I went swimming."

Rimmer didn't have time for this. "Look, can you give me some of his personality traits or not?"

"Whose?" Holly asked.

Rimmer rolled his eyes. "Lister's."

"Should be able to, yeah," Holly said. "Which ones do you want?"

"Does it matter? Just give me a few at random," Rimmer said.

"Right," Holly said.

Rimmer swayed on his feet. Getting new information in his head was like having a faucet turned on; he could feel the water running in his brain, and it made him dizzy. "Have you done it, Hol?"

"It's done," Holly said.

"Thanks," Rimmer said, turning and heading for the bunk room. He couldn't be sure, but he suspected that the loose, casual strides he was taking down the corridor were Lister's.