A/N - This is what popped into my mind (amongst many other Howadette thoughts, so cute) at the end of The Proton Resurgence. It reminded me of how much Penny loved Leonard talking science, and also how much their relationship has grown this season. (And yes, I had to google the potato experiment...) Apologies if I haven't written the who potato thing correctly - enjoy, and let me know what you think!


"Leonard?"

"Yeah?"

He looked up from packing up the experiment kits into the suitcase, which had been left by Professor Proton. She was sat on the couch, looking at the potato still on the table in front of her.

"Can you tell me how this whole potato clock thing works?"

"Are you still on that?" He raised a brow as she nodded at him, and he came to sit next to her. "Okay. The potato acts kind of like a battery - it's an electrochemical cell."

"I'm sorry, a what?"

"It converts chemical energy into electric energy."

"Of course," She nodded, frowning. "Continue."

"So... you see this?" He indicated to the potato. "This nail is coated in zinc, and this is a copper wire - the electrons transfer here. The potato conducts electricity, but it keeps the zinc ions and copper ions separate."

"Uh-huh," Penny began nodding slowly.

"So-o, the electrons in the copper wire are forced to move, which is what generates the current, and makes the alarm clock work."

"That is so cool!" Penny grinned. "So if I run out of batteries in my alarm clock, I can just use a potato?"

"Penny, your alarm clock is broken." Leonard pointed out. "You threw it across the room when I set it for five in the morning. A potato isn't going to revive it."

"Hmm, I suppose not. Still, the idea of it is pretty cool." She paused for a moment. "Can you explain it to me again?"

"Sure. The-"

But he didn't need to, because next thing he knew, Penny's mouth was on his, and they were making out in front of a potato.


Once their clothes were back on, and Professor Proton's suitcase had been finally packed up, Penny flashed Leonard a grin.

"You know, one day when we have a kid, if they say 'pagsetti' - that's totally your fault." She giggled when Leonard just stared at her, frozen. "I'm going to get my jacket and then we can go check on Professor Proton."

Leonard's jaw dropped slightly when she left. When they had a kid. Not if, when. He grinned, doing a happy dance as he walked over to his desk chair to pick up his jacket. He pulled it on, and then shrugged his shoulders forward.

"Just play it cool, Leonard. Play it cool."