Sheldon went to work. He didn't have anything else to do. The buses weren't running, so he walked. The university was echoing and empty on New Year's Day, and he could concentrate properly. No grad students in stupid shoes or nosy administrators or people wanting a signature on a postcard because someone had a baby or a funeral or some absurd thing like that. Or nosy roommates. Or girls, with white legs and sad eyes. Just him and the delightful chemical smell of the dry-erase marker.

It took him most of the day to work through the calculation. He didn't even notice he was squinting by the time he was done, the daylight almost gone.

Sheldon clapped himself on the shoulder. "Well done, Dr. Cooper! Now, to the mainframe!" He could set the simulation running overnight.

For the most part, he decided, it had been a good day. Sheldon stepped out of his office and nearly ran into Kripke, whom he had last seen drooling on his spot that morning.

"You missed a great party, Cooper!" Kripke said, falling in next to him. "Of course, it probably wouldn't have been so great if you were there. Still, your girl Amy is a party animal."

"I'm sure she is," Sheldon said. He was not going to think about Amy. He was going to think about his simulation.

"You going to see her now? Must be convenient to have her working here. You can take her straight home…" Kripke waggled his eyebrows in a completely offputting manner.

"I am going to the mainframe in Buckman," Sheldon informed him.

"…get her out of those glasses and cardigans…" Kripke whistled and made a shape vaguely resembling a stylized female body with his hands. "I'm telling you, if you ever break up, I am next. In. Line."

Then what he was saying caught up to Sheldon. "Amy is here?" Sheldon asked.

…and what Sheldon was saying caught up to Kripke. "You're going to the mainframe in Buckman?"

"Yes, I am. Amy is here?"

"Ran into her in the cafeteria with Wolowitz. Some robot rat grant proposal.I came in especially on New Year's Day. I'm going to the mainframe in Buckman."

"No, I am." Sheldon said.

He remembered Howard saying something about checking with Amy about a project. He couldn't remember any robot rats. I'd like a robot rat, if Amy builds one, he thought.

"The hell you are!" Kripke shouted, and took off sprinting down the hall.

Sheldon frowned after him. Why…?

The mainframe!

He wasn't the world's best runner, but neither was Kripke. Along the hall, down the stairs, through the empty cafeteria - he was gaining - past the lobby - he nearly had him - across the parking lot…Sheldon skidded to a halt. That was Amy's car.

So? So it was Amy's car. Kripke was getting away.

Sheldon chased the other man into the computer lab, just in time to crash against the door before Kripke shut it in his face.

"You can't have it! I could be out right now, meeting chicks who's new year resolution is to stop dating hot men with tattoos!" Kripke panted. "And I put my name down a month ago!"

"But my simulation isn't dumb," Sheldon said, hands on his knees.

"Get out!" Kripke said.

"You get out." Sheldon straighted. "I'm not going anywhere."

"I booked this time."

"There's no need to yell," Sheldon said. "You can do your thing tomorrow."

"You can do your thing tomorrow."

"But I don't want to, and my thing isn't dumb."

He didn't want to go home. He didn't want to go into his bedroom in particular, where books and model trains and his transformer doll were still scattered across the unmade bed.

Kripke set his jaw and took a step towards Sheldon…and Sheldon hit him.

Well, he tried. Well, it was more of a swat. Maybe, more accurately, a flail. Kripke swung back, aiming for Sheldon's nose but grazing his elbow instead. Sheldon pushed him and nearly fell down. Then Kripke, via a stroke of the fortune that smiles upon those dealing with madmen, managed to land a real punch on Sheldon's jaw.

The pain was sharp, sudden, and clear as a bell. And it felt good.

Suddenly, the two scientists weren't fighting like sleepy bunny rabbits on stilts, but, if you squinted, like something tangentially approaching men.

Sheldon lunged at Kripke and knocked him back against a server rack. Kripke managed a sharp elbow in Sheldon's ribs, but then Sheldon had Kripke's lapels in his hands. He slammed him against the rack again. "Stay away from my…from my mainframe!"

Kripke twisted out of Sheldon's grasp and scooted across the room to the main terminal. "It's not your mainframe!"

And who's fault is that? Sheldon thought. "That doesn't mean it's yours either!"

He stalked after Kripke, but the other physicist had already sat himself firmly down and was logging in.

Then Sheldon spotted the box of cable ties.