It was 7 a.m. and he'd slept for maybe two hours the night before, and that only because he'd passed out on his books. He knew Sam hadn't gone home either, and she looked as tired as he felt. It wasn't really a great time for deep and meaningful conversation, but he'd been dreaming and now he was thinking despite his best efforts not to, so when Sam asked him what was on his mind, he decided not to brush off the question.
"I was thinking about alternate realities," he said.
"This early in the morning?" Sam took a big gulp from her cup of coffee to emphasize her point.
"Not about the physics; I couldn't make sense of that even if I was awake. Just about...what might be different in other realities."
Half asleep or no, Sam knew him well enough to see where this was going. "Daniel..." she said in that 'Oh, you poor dear' voice that he was getting sick and tired of hearing, which in this case translated to 'Why do you have to torture yourself with these kinds of thoughts?'
Deciding to disregard that, he went on: "It's just interesting to think about. There are a lot of different possibilities. It could have been you or Jack who came, and you would have used a gun or a zat, which might not have killed—"
"Or you could be dead," Sam broke in, voice surprisingly harsh.
"I'm dead in a lot of realities," he said dismissively. "What's one more?" Before she could object to that, he continued. "That's not the point."
"Then what is?"
"There must be at least a few other realities where Sha're's alive," he declared. Sam just looked at him, and he was aware that she was trying to hold back that pitying look she knew he hated. "I know we can't go to other realities anymore, but that doesn't mean they don't exist."
"What difference does it make if you can't go there?" Sam asked, clearly not understanding how knowing that alternate versions of himself were happier than he was made anything better.
"Look..." He searched for the right way to explain his feelings. "When I went to the alternate reality that was being destroyed by the Goa'uld, they helped me get back here because even though it was too late to save their reality, ours still had a chance. It made them feel better to know that there was an Earth that might be okay, even if theirs wasn't." Sam was nodding; she got it now. "So even though Sha're is dead in this reality and I'll never be able to see her in another one, it helps a little to know that there's some reality where she's alive and free and happy."
"And so are you?"