I've never actually been on a train, so I don't know if you need a train ticket. I'm just following Harry Potter and his ticket for Platform nine and three quarters.

Penny tossed and turned in her bed, she was still fuming at what Sheldon said to her earlier. I have to get back at him, she thought. Penny sat up in bed; her alarm clock said it was 1:30 in the morning.

She couldn't go to sleep with vengeance on her mind.

"What does Sheldon love?" she said out loud. Penny thought for a long time, eventually her mind clicked that Sheldon was going to San Francisco tomorrow, well... technically today, by train.

"HA" Penny laughed out loud and snapped her fingers,

"That's it! He loves trains!" An evil, diabolical plan formed in her head.

Penny grabbed her spare key and opened the door to Leonard and Sheldon's apartment. She easily found Sheldon's suitcase with his train ticket on top. A smile crept on Penny's face as she took his ticket and went back to bed.

*

Next morning, Leonard was making oatmeal for oatmeal day, when Sheldon walked in the room with a smile on his face and a bounce in his step. He was going to catch a train today.

"Good morning, Leonard," Sheldon said cheerily.

"Morning," Leonard groggily responded, he was driving Sheldon to the train station.

Leonard handed Sheldon his oatmeal, then Sheldon walked past his suitcase on the table, to sit at his spot. The moment Sheldon sat down, his expression became alarmed;

"Something's wrong."

Sheldon looked around to spot the difference, and then pointed in horror at his suitcase.

"What's wrong, Sheldon?" Leonard asked, really annoyed at Sheldon probably panicking over nothing.

"My train ticket is gone!" Sheldon stood up, almost spilling his oatmeal, looked around him frantically. He turned to Leonard and asked in a frightened voice, "Did you put it somewhere, or ...misplace it?"

"No I didn't even touch it" Leonard responded. He watched as Sheldon looked under and around his suitcase. Sheldon is really worried, thought Leonard.

*

Penny woke up with a sore mouth; apparently she went to sleep with a smile on her face.

She looked at her alarm; it was 10:25 am. Sheldon and Leonard would leave for the ride to the train station in five minutes. It was the perfect time for revenge.

She grabbed the ticket, and walked with confidence to Sheldon's apartment.

*

"I don't know where it is Sheldon!" Leonard shouted.

Sheldon looked at his watch, "Oh no. It's past the time to leave Leonard."

"Do you think someone broke in and stole it?" Leonard asked sarcastically, to get Sheldon's mind off the time.

Sheldon's face changed with confusion, "Who would want to steal my train ticket?" Then Sheldon's mind clicked and his face changed into contempt and fury.

Sheldon faced the door as it opened, seeing the person he despised more than any of his other enemies; Penny.

"Good morning boys!" Penny yelled.

Penny smirked at the priceless face on Sheldon; he once gave her that look when she prevented him from doing laundry on laundry night. "Hey what are you two still doing here? It's two minutes past ten thirty; shouldn't you guys be driving to the train station by now?" She put on a fake confused face.

"My train ticket is missing," Sheldon muttered.

"Really? Well that's too bad," Penny put both her hands up, one of which had Sheldon's train ticket in, "I have no clue where it could be." She put on a tight smile and said, "Sorry," then slammed the door.

Leonard's mouth was wide open with shock. But Sheldon was quick to react to the confirmation that Penny was a thief. He ran out the door, and caught sight of her just before she entered her apartment.

"Give me back my ticket Penny!"

*

Penny slammed the door and leaned against it, waiting for 'the knock'.

"Penny."

Knock, knock, knock.

Penny's stomach turned with butterflies, thinking maybe she crossed an even further line than he went.

"Penny!"

Sheldon's voice awkwardly got louder, as if he was trying to keep his emotions under control.

"PENNY!"

Penny opened the door, a tiny crack, and could Sheldon twitching uncontrollably, "yes Sheldon?"

Penny asked with the tiniest hint of concern. But of course, Sheldon didn't notice,

"Give me back my ticket," his fierce command and piercing eyes, struck Penny with fear that made her heart skip a beat. The feeling of fear of Sheldon shocked Penny, turning her fear into anger.

"Apologise to me about what you said to me last night, and I'll give the ticket back to you," Penny knew from their last battle; how to stare off with Sheldon.

"Apologies for what? Telling the truth?"

"Say goodbye to your ticket," Penny was closing the door.

Sheldon stopped the door, "Alright, alright."
Penny opened the door wider; to better hear his words, "I'm waiting."

Sheldon looked Penny in the eyes, and sounded sincere, "I apologise, for what I said last," his voice went an octave lower, "I had not realised that opinions are no longer seen as opinions, but are seen as insults and ego-destroyers." He gave Penny a cold look.

That was not an apology in Penny's mind, so right in front of Sheldon; she ripped the ticket into pieces and dropped them on the floor.

"Don't bother getting angry Sheldon! It's almost eleven, you would've missed train!" Penny slammed the door.

*

Unknown to Sheldon and Penny; Leonard, Howard and Raj had watched that entire fight.

When Penny slammed the door, Sheldon stormed past the three of them and into the apartment. He grabbed his suitcase and headed back out the door, "Come on Leonard, I'm catching the next train to San Francisco. This delay will affect my entire trip," Sheldon gave one last look at Penny's door, and then went down the stairs, suitcase in hands.

As he was walking, Sheldon muttered, "This isn't over, Penny."