David was so incredibly overwhelmed by everything he had learned about Stargate Command over the past three days. He'd been given the official briefing and signed all the nondisclosure statements without hesitation and was already being introduced to the inner workings of the SGC. He'd shoveled his way through the first two years of mission reports and was anxious to read them all.

He was particularly enthralled by the flagship team, SG-1, and their incredible discoveries and adventures. Despite the fact that he should have been more interested in the technical and scientific reports of Major Carter, he actually preferred reading Colonel O'Neill's reports. They were so much like the man he had seen only a few times: succinct, full of character, and with hidden depths of knowledge and insight that could take you by surprise.

He had been allowed to look at the Stargate up close a couple of times, but today would be the first time he'd get to see it in action. SG-1 was coming back from a mission (as scheduled, for once, which seemed to be a slightly morbid joke among the technicians that operated the Stargate because of the number of times the team got into unexpected trouble) and he had been given access to the Control Room to see it.

He waited unobtrusively in the back, arms folded across his chest. If he wasn't so excited about what was about to happen, he'd probably be bored out of his skull.

Exactly two minutes after the scheduled check-in the inner ring of the Stargate began to spin and the dark orange chevrons lit up. He gasped involuntarily and took a step closer, just as General Hammond arrived.

"First time, Dr. Granseth?" the elderly General asked with amusement.

"Yes, sir," he replied dumbly, too enthralled to comment further. He was grateful when the General didn't call him on it.

As the wormhole shot out and settled inside the metal ring of the Stargate he was speechless. He'd never seen anything so amazing in his entire life, it was breath-taking. Absolutely incredible. The effect was only multiplied as four figures emerged, and it boggled the mind to think that they had been thousands of light-years away only seconds ago.

Despite the wonder of the alien device in action, his eyes settled on Colonel O'Neill. What was it about that man that seemed so familiar? O'Neill pulled off his sunglasses, which were attached to a cord around his neck, before he unclipped the P-90 at his chest and handed it to another airman.

The General was entering the Gate Room as the rest of SG-1 walked down the ramp, and he could just hear their conversation through the microphones in the Gate Room. "Welcome back, SG-1. How'd it go, Colonel?"

"No sign of the Goa'uld or any other civilization, according to Daniel and Carter's readings, but I wouldn't recommend it as a possible safe world for resettlement."

David could see the smiles on the faces of O'Neill's teammates, except for the Jaffa, Teal'c, who had an eyebrow raised in almost a quizzical manner.

"Why's that, Colonel?" the General asked.

The Colonel pulled off his hat and ran his fingers through his hair vigorously. "Intuition?" he offered, weakly.

Confused, Hammond looked to Major Carter for an explanation.

"He's got a headache, sir," she explained, failing to hide the smile.

"He was being a grouch," Dr. Jackson added shamelessly. "He swears there has to be something on that planet that caused it, but…you never know."

O'Neill scowled at his teammate. "I am not a grouch. I have a naturally sunny disposition."

That earned a snort of disbelief from the General, and David found himself grinning along with the banter of these people. He had no idea that military personnel could be like this while on duty.

"Get yourself checked out in the infirmary, Colonel. We'll debrief in one hour."

"Yes, sir," the Colonel complied, rubbing his eyes with his thumb and forefinger as he walked through the door.

Rather anti-climactic for an SG-1 mission, but he supposed that was a good thing.

--

Hours later, Jack sat hunched over a table in the commissary, his tray shoved to the other side of the table as he cradled his head in his hands. He was hungry but he couldn't bring himself to eat because of the splitting headache that made him nauseas just to move. The lights were too bright, the noise was too loud, and he seriously needed to have a talk with the guy with the hammer in his brain.

"If you don't mind my saying so, Colonel, you look terrible."

Keeping his head suspended in his left hand he put on his hat with his right hand, pulling the bill down to conceal his face. There was quiet, amused laughter from the other side of the table.

"That is not what I meant. May I join you?"

He waved his hand, inviting David Granseth to join him but remaining silent, with his eyes closed and his head down. He massaged his neck a bit, but it did nothing to relieve the tension in his head.

He was surprised by the silence. Usually, the scientists he worked with couldn't stop talking long enough to eat with their mouths closed. David had to have a thousand questions but maybe he was smart enough to recognize that talking to a Colonel with a migraine was like talking to a bear with a sore head. Not worth it.

It was at least fifteen minutes later, long enough for David to finish his lunch, before the scientist finally spoke again. "Should you not be in the infirmary, Colonel?"

Jack shrugged his shoulders and adjusted his hands to rub at his temples.

"Come on. I'll help you down there."

He didn't resist as gentle hands helped him stand up and practically carried him down to the infirmary. As he was laid down on one of the infirmary beds he opened his eyes, just a slit, and gazed up at David who was leaning over him as he helped him set his head on the pillow gently. "I missed you," he whispered, then was promptly unconscious.

--

David stared down at the Colonel in disbelief. He must have been mistaken for someone else, this Jack O'Neill couldn't possibly know him.

"What happened?" Dr. Janet Fraiser asked him as she quickly examined the Colonel.

"I found him in the cafeteria, holding his head like he had a headache. He hardly moved for twenty minutes. He looked so miserable I thought you ought to check him out."

"Yes, thank you for bringing him in."

"Is he going to be okay?"

"Don't you worry about the Colonel none. I'll take good care of him."

He knew that was his cue to take his leave.

He walked back to the lab to which he was assigned at the moment and resumed the work he had been doing before his lunch break, which was mostly becoming acquainted with the equipment and organization in the lab. For the most part, his current assignment was reading up on the reports of experiments done on materials that had been brought back through the Stargate, namely the mineral Naquadah that the Goa'uld used in most of their technology and that made up the bulk of the Stargate.

His mind drifted back to the Colonel, unable to focus on anything else for the moment.

Jack O'Neill. The name alone was enough to bring back painful memories for him. There was always a part of him that could never really believe that the Jack he knew had never really existed as flesh and blood. He had vivid memories of watching hockey games, of wiping blood off the face of the younger boy after he'd been in a fight, of heart-breaking angst wondering if his brother was going to come back this time, and elation when he finally did. Jack was so much a part of his life, had changed the way he looked at the world and at others, that it was impossible his little brother didn't exist.

Yet there was so much evidence to the contrary. Before he and his father moved to another town he'd searched every corner of the house when he had finally recovered from the pneumonia, but there was nothing that he had come to associate as his brother's. His clothes, his books, his hockey gear, even his bed, there was nothing there. The only things David could find were the presents Jack had given him: a book on astronomy and a pocket knife. He remembered how hard Jack had worked to scrape up enough money to buy that book, not knowing why his brother had wanted the money so badly at the time. And he remembered the sheepish smile on Jack's face as he handed him the pocket knife. "To help you fix things. There's more to it than you'd expect. Kinda like you," Jack had said.

Dad had explained that he had actually been the one to buy him the book, and that he'd found the pocket knife on the ground and thought David might like it. He still treasured those two gifts, and the memories they'd entailed, even years after he had finally accepted that Jack was nothing more than an illusion his mind had created.

There were other signs, as well. Jack's sudden appearance in their lives and Dad's indifference to the younger boy no matter what Jack did. The way Jack never considered his own safety when David needed protection. And, of course, what Jack did the last time he ever saw him.

Some nights he could still feel Jack's hand on his forehead, fighting his battle for him as he had always done.

He could still see that image through the back window of the car, his brother kneeling in the middle of the road as he was taken away from him, unable to go back to him. In his dreams, he'd shout at his father to turn around, to go back, and Jack would be there, waiting for him.

He remembered his brother's tears as he told the younger boy that he was special, and how proud he felt at that moment, of his brother and of himself. That was the day he had finally felt like a man, not a boy. It was the day he began to stand up for himself.

It was only after Jack was gone that he began to stand up for others as well. In his heart, he felt that if he had been able to turn that car around, to stand up for Jack against their father, then maybe Jack never would have left.

For him, an imaginary brother was better than no brother at all.

He missed Jack.

Colonel Jack O'Neill missed somebody, too. He wondered who it was.

--

Forty years ago

"Jack, where have you been?" David exclaimed as Jack limped through the door. He pulled his younger brother into a hug before checking him over for injuries. "What happened?"

Jack shrugged away from David, head lowered, his feet shifting. "I went for a walk."

"A walk? Jack, you've been gone for three days. I was afraid something had happened to you. Are you hurt?"

"I'm fine," Jack replied, still looking away.

David sighed, recognizing his brother in his stubborn phase. "Alright, you go get cleaned up and I'll get you something to eat." As Jack started to walk away he called out, "And Jack?" He waited for Jack to look at him. "I missed you."

Jack smiled a little. "I know."