Kaylee stood bent double over one of Serenity's engines with the upper half of her body almost inside of it. She was using all the strength she could muster to try and loosen a very stubborn bolt. She huffed in irritation, the stupid thing simply would not budge. She heard a set of heavy footsteps come up behind her, but the person didn't speak.

"Well, don't just stand there. Make yourself useful," she said to the unidentified person.

Without straightening up, she handed the wrench she had been using to the person and gestured blindly towards her toolbox, "Hand me a longer wrench."

Whoever it was still didn't bother saying a word, but she could hear rifling through her tools and a different wrench was soon slapped into her palm. She attacked the bolt with fresh vigor, hoping the slightly longer wrench would provide improved leverage. She pushed on the wrench with all her might, but the only thing that moved was the wrench itself. It slipped off the bolt causing her to scrape her knuckles and the back of her hand. She cursed and stood up to examine the injury. She sighed.

Not even enough damage to bother seeing the doctor over.

The thought of Simon made her turn around to see if just maybe it was him that had come into the engine room without a word. Instead Jayne stood there staring quietly at her. He moved forward and took her injured hand in his.

"Not too bad," he said. "We can fix this up ourselves. No need to bother Doc."

His hand slid up to her wrist and he led her to the infirmary. He turned the water on and waited for it to get warm.

"There, wash it while I find some bandages and tape."

She washed her hand carefully, being certain to remove all the engine grease from around the abrasions. Then she patted it dry and walked over to lean against the exam table. She watched as Jayne continued searching through drawers and cabinets. Finally, he walked over and laid a tube of some kind of ointment, a roll of gauze, scissors, and tape on the table beside her. He took her hand in his again and squeezed some of the ointment on it. Kaylee silently noted that his hands were rough and callused.

Just like mine, she thought. She was the only female mechanic she knew of; and according to the captain, the best.

Once Jayne had finished bandaging her hand she looked up to thank him, but the intense look in his blue eyes took her breath away. He raised his other hand and cupped her cheek, and lowered his mouth to hers. For a moment, Kaylee was too shocked to react.

She had imagined Simon kissing her. In those daydreams, the doctor's lips had been soft and tender. Jayne's were firm and persuasive; his beard tickled her face. He pulled back to look at her again.

She wasn't sure whether she wanted to slap him or kiss him back. He took the decision out of her hands by covering her mouth with his again.

This time, he teased her lips apart with his tongue and deepened the kiss. His mouth tasted like coffee sweetened with sugar and milk. Kaylee's heart was pounding so hard, she was certain he must be able to hear it. She wrapped her arms around his neck. He was so tall she had to rise up on her tip-toes. He put both his arms around her and pulled her closer. She had seen this man everyday of her life for the last several years, how was it that she had never appreciated just how muscular and strong he was?

Suddenly, the kiss was over. Jayne put his lips right next to her ear. His warm breath made her shiver as he whispered,

"I had to do that just once, before that genius doctor gets all those brain cells working and realizes what he's missing."

He stepped back from her, turned, and walked out of the infirmary. Kaylee stood there stunned, trying frantically to make sense of what he'd just said. Finally, something clicked into place in her brain.

"Jayne wait!"

A/N: I know a lot of "Firefly" fans were happy to finally see Kaylee and Simon get together at the end of "Serenity," and I admit I was one of them. However, I always wondered, what if? What if the reason Jayne disliked the doctor so much was that he had a thing for Kaylee himself and just never got around to telling her. I thought of this story as an alternate story line falling somewhere between the end of the TV series and the beginning of "Serenity." It's intended as a one-shot, but I could see a series on one-shots expanding on their relationship evolving from it.