Spoilers: Serpent's Venom

Jack was home alone. His father and David had gone into town to the local hospital because David wasn't feeling well. Pop was always careful about David's health, though Jack could be bleeding from the eyes and he'd be ordered to sleep it off. However, he thoroughly approved of the over-protectiveness towards David's health, so he didn't complain.

He lay down on his belly on the floor of the living room close to the fire, propped up on his elbows, his book for English opened up in front of him. English was his favorite subject, and the only one for which he completed all his homework, sometimes doing more than was required of him. His math he did reluctantly with David's help, history was okay because he liked reading some of the stories though he could never remember all the important dates and places. He hated science. He just wasn't meant to be a scientist, that was David's job.

Prepositions. Now there was something he could understand. Never end a sentence with a preposition.

"John!"

Jack nearly jumped out of his skin as the front door slammed open, a gust of cold wind accompanied by his father. His father did not look happy.

He closed his book and jumped to his feet as his father stormed by him.

"Pack a bag for David. A couple days worth of clothes. And find that book he's reading, the big one with the stars on the front."

"Is he okay?"

"Just shut up and do it! And pack something for yourself, too, we're staying in town."

He didn't bother to ask any more questions. He ran to the bedroom he shared with David and packed both their bags in about thirty seconds flat, picking up the book with the stars off the dresser as he ran out the door. Pop was still rummaging around his own room so Jack crouched down on the floor by the front door and straightened out and neatly folded David's clothes so they wouldn't get wrinkled. David didn't like his clothes wrinkled.

"Put the fire out!" Pop yelled at him from the other room.

Jack scowled. He ended that sentence with a preposition. Jerk.

Five minutes later they were in the car, driving the icy roads into town. He knew it was foolish, he knew he'd just get in trouble, but he had to know. "What's wrong with David?"

"There's nothing wrong with him! He's gonna be fine."

"Then why did you leave him at the hospital?"

"Because I had to take care of you! One drunken mistake and I get stuck with you for life. Why your mother dumped you on me I'll never understand."

"I didn't ask to be stuck with you," he replied bitterly, looking out the side window. It wasn't his fault his Mom couldn't afford to take care of him anymore, and had decided that he should live with his father, a widower who had taken advantage of her to handle his grief.

"If David wasn't so fond of having a little brother I'd send you to the orphanage. You're more trouble than you're worth. My son needs me and instead of being there for him I have to make sure you don't get in trouble. Could you at least try to be more like him, just this once, pretend that you're a good boy?"

He glared straight ahead, just managing not to bare his teeth and growl. He'd been doing his homework by the fire, how was that causing trouble? "I'll behave myself for David," he promised through clenched teeth, "if you tell me what's wrong with him."

"You wouldn't understand."

"Maybe I would if you let me."

"He's sick! My son could be dying! And you, you've got your perfect health, not so much as a damn cold, but my brilliant boy who's got so much to offer to this world might not make it through the winter!"

Jack felt his chest tighten, ignoring the anger and condemnation in Pop's tone as he usually did, and hearing only the news that his brother was dying. "David's…He's…"

"Just shut up. I don't want to talk about it."

"But…"

"Jack!" The car swerved on the ice as Pop wrestled to get it back under control while fighting the urge to backhand the boy next to him to get him to stop talking.

Jack cowered into his seat, making himself as small as possible as he tried to think about what was happening to his brother. He knew David had been sick for a while, and he'd been so weak lately he couldn't even walk home from school anymore, but he didn't know it could be so bad.

They finally got to the hospital and Pop didn't wait for him as he grabbed David's bag and ran through the doors, leaving Jack confused and lost. He saw David's book still on the seat and picked it up, leaving his own bag on the floorboard. He slammed the door shut, making sure it wasn't locked, and walked into the hospital.

He looked around, unsure where David would be, so he decided to search each room until he found him. It took him five minutes to find the proper room, where he could hear his father's raised, pleading voice. "He's all I've got left. You have to do something."

Those words didn't hurt him anymore. They should have, but they didn't.

As he listened through the open doorway he heard a male doctor's voice speaking in low, calm tones as he explained David's condition. He couldn't hear everything, but he got the gist of it. David had something called acute leukemia, which affected his immune system and made him more susceptible to pneumonia. The doctor could try to cure the leukemia with a drug called 6-MP, but with David already so sick from the pneumonia, the chances of recovery were very slim.

There was a long silence in the room and Jack peeked inside to see what was going on. Pop was crying. He had his face buried in his hands and the Doctor was patting his shoulder. Jack slipped into the room and sat down in the corner, hugging his knees with David's book pressed up to his chest. He didn't think Pop was capable of tears.

As soon as the doctor left he stood up and approached the bed where David was sleeping, moving quietly so he wouldn't disturb Pop. He studied his brother's face, which was slightly flushed from illness but otherwise relaxed in sleep. He set the book down on the bed beside him and just as quietly left the room.

He walked through the hospital until he found a room with lots of books in it, and he crept in and studied the bindings. They were obviously all medical books, but he wasn't sure exactly what he was looking for. He picked up one of the larger ones and pulled it off the bookshelf, setting it down on the floor and kneeling over it as he opened it to the back and looked through the index.

He wasn't sure how to spell leukemia but he didn't find any words under 'L' that looked right so he put the book back and pulled down another one, this time noting that the title mentioned immune diseases. He found the word in the back and turned to the appropriate page to find out what was killing his brother. As he read, he had to look up even more words to understand what they were, so within half an hour he had four books on the floor and open to different pages.

"What are you doing in here?" a male voice asked from the doorway and he jumped a little at the unexpected intrusion.

"I had to look up something," he explained, glancing over at the man, who was wearing the clothes of a janitor.

"Did you get permission to be in Dr. Fielding's office?"

He sighed, knowing he'd have another reprimand coming but not really caring. "No. He'd have said no. He wouldn't think I could understand this stuff."

The janitor knelt down beside him and glanced over the pages. "Leukemia?"

Jack nodded his head. "That's what the doctor said David has. I wanted to know what it was."

"He wouldn't tell you?"

"I didn't ask."

"Do you understand it now?"

Jack shrugged. "Not all of it, but enough. He's dying."

David was going to leave him behind with a father that didn't want him. Pop only wanted the good son, Jack was just an inconvenience.

Well, he was going to be there for David until the end, he didn't care what Pop had to say in the matter. He had to protect his brother.

---

Thirty-eight years later

Jacob Carter ignored Jack's sarcastic remark about the potential mission to the Tobin mine field being an insane idea. "Obviously, I'll need Dr. Jackson, and there might be some complicated mathematical calculations to be done, Sam would be a big help, too."

A throat cleared suggestively.

"Of course, Colonel O'Neill is…always lots of fun to have around."

Jack was used to being an inconvenience. He didn't mind.