That afternoon, Leonard and Sheldon got home from work.

"All I'm saying is that with the right technology, I could be Batman," said Sheldon as he and Leonard walked up the stares to their door.

Leonard looked at Sheldon. "Didn't we already have this conversation?" he asked as he opened the door.

They walked inside. Right after Leonard closed the door behind him, Sheldon stopped and said, "Something's wrong."

Leonard gave him a quizzical look. "What?"

"I sense a disturbance in the force," said Sheldon.

Leonard rolled his eyes and went to get a soda from the fridge. Sheldon walked back the hallway to his room.

Leonard sat down in his chair and was about to turn on the television when suddenly Sheldon came hurrying back into the living room.

"Leonard, this is bad," he said.

"What is it?"

"Someone's been in my room," Sheldon said.

Leonard got up. "How do you know?"

"Come and see." Sheldon and Leonard walked back to his room. Sheldon pointed to a container of glass vials on his shelf. One of the holders was empty.

"There were ten vials here, Leonard. One of them is missing."

"Maybe you misplaced it," suggested Leonard.

Sheldon glared at him. "I never misplace anything, Leonard. Especially not something as important as this."

"What is it?" asked Leonard.

"Remember when I wasn't working and I was experimenting with Goldfish and Jellyfish DNA?"

Leonard groaned as he remembered that horrible time. "Yes."

"Well, I was also doing some other research that I never told you about."

"Like what?" asked Leonard.

"After the recent Mars probes brought back some soil samples, I was able to obtain a small portion of the sample from Wolowitz, who was working with the Mars probe at the time. I discovered trace amounts of DNA in the sample. Very aggressive DNA, as it were. And after performing several experiments on it, I decided to post pone more research because by then I had gotten my job at the university back."

Leonard stared at him in shock. "You've been performing unauthorized experiments on alien DNA?" he exclaimed.

"Yes, and now one of the vials is missing, which is very bad."

By the expression on Sheldon's face, Leonard could tell he was serious.

"Okay, okay, lets just calm down," said Leonard. "Maybe Penny knows what happened to your vial. Lets just go over there and ask her."

"Oh, I hate to think what horrors could unfold if she opened it," said Sheldon.

They walked out of there apartment and went over to Penny's door. Sheldon knocked.

KNOCK-KNOCK-KNOCK, "Penny?" KNOCK-KNOCK-KNOCK, "Penny?" KNOCK-KNOCK-KNOCK, "Penny?"

After several times of this and still know answer, Leonard said, "Here, Let me try." Leonard knocked on the door. "Penny? It's Leonard. If you're in there, we really need to talk to you."

They waited, but still, know one answered.

"Well that's weird," said Leonard. "I saw her car parked in front of the building." Leonard decided to let himself in. He slowly opened the door and they looked inside. What they saw made their jaws drop in horror.

There in the center of the room, was a large xenomorph queen, just like in the movies, with the massive egg tube sticking out the bottom of her. And all around her were dozens and dozens of large eggs.

Leonard and Sheldon gapped in horror. "Oh my Gawd," said Leonard, realizing that the girl he loved was now the hideous monster in front of him.

Suddenly several of the eggs in front of them opened up like flowers. Inside each of them something was stirring.

"Oh shi-" began Leonard when two face huggers leapt out of the eggs and latched themselves onto Leonard and Sheldon's faces. The two fell backwards in the hallway and passed out while the face huggers began to impregnate them. The other face huggers scurried out the open door of Penny's apartment in search of others to impregnate.

Two days later, the alien infestation of Pasadena had gotten so bad; the government had no choice but to nuke the entire city in order to prevent the infestation from spreading any further. In the end, nothing was left of Pasadena but a pile of rubble. Millions of lives were lost, all because someone went into Sheldon Cooper's room.