A/N: Thanks for the great reviews, everyone! It's nice to know that people are enjoying the story, and itmakes it much more fun to write it! Once again, sorry for the time delay in updating. One of these days I'll get my act together! This chapter is pretty short, but hopefully pretty sweet, too :) Enjoy!

But Jack couldn't figure it out. Just when he thought he had isolated the M.O. of this particular poison, Kate's symptoms would change suddenly and he'd be back at square one.

The mysterious rash had disappeared as quickly as it had developed, but Kate said she still had a slight numbness in her chest. All of the swelling in her arms had dissipated, too, but she was experiencing sharp spasms of pain from time to time, causing her to cry out in her sleep, and only adding to Jack's increasing anguish that he couldn't cure her.

He had felt a wash of relief when Kate's fever had broken in the middle of the night, but now she was shaking uncontrollably, unable to get warm in the damp cave. Jack had moved her as close to the fire as was safe and he had exhausted his stock of extra blankets. It was almost as though Kate's system had spent so long trying to bring her down from the fever that it was stuck in cooling mode and had forgotten how to warm her up.

Jack had suggested that Kate try to get up and walk around to get her blood pumping, but she was both too weak and too dizzy to manage it, even with his help.

"Any better yet?", he asked hopefully, throwing more kindling onto the fire.

"A little," Kate managed, her voice shaking.

"Well, the sun will be up in a few hours, and then I'll be able to get you outside and warm you up, ok?" Jack was trying his best to sound positive, but the expression on Kate's face told him it wasn't working.

She nodded her head and tried to smile, wanting to ease Jack's worry. She knew he hadn't really been sleeping much over the past few nights, and she hated that it was because of her.

"I'll be fine," she said aloud, wanting to reassure Jack. But it came out more as if she was trying to convince herself, and Jack gave her a small smile.

"Of course you will. We just have to get you warm."

Jack got up from his seat by the fire and Kate heard him rummaging through a suitcase behind her.

"I knew I saved this for a reason," he said as he returned to Kate's side.

She looked up to see him holding a suit jacket; the same one she had seen hanging from a tree the day she had sewn him up on the beach. Kate remembered how scared she had been when she'd seen the blood and realized what Jack was asking her to do, but he had helped her though it, just like he was doing now. Just like always…

Jack seemed to be remembering that day, too, because he smiled and said, "Don't worry. I washed it."

Kate smiled back as another shiver coursed through her body. She shifted onto her side so that she was facing the fire, and Jack bent down and laid the jacket over her, tucking it in close to her body. The jacket smelled like him, and Kate involuntarily took a deep breath, letting the familiar scent fill her lungs. Jack reached out to sweep a stray curl from her face, and she closed her eyes and leaned into his hand when it lingered on her cheek.

"You're warm," she said quietly.

Jack didn't answer, but instead lowered himself down behind her, putting one arm around her waist and pulling her close to him. Kate felt his warmth enveloping her, seeping into her body through the layers between them. She wiggled one arm free from the blankets and laced her fingers over top of his, pulling his arm tighter around her stomach.

"Jack," Kate whispered, her voice wavering as another tremor shook her body. "I'm scared."

He squeezed her hand and remained silent for a moment. Then he bent his head in closer to hers, and Kate could feel his breath in her hair as he slowly began to count.

"One… Two… Three… Four… Five."