1) They started out sharing a tent, and soon were sharing bedrolls. It was a natural progression, from four individual sleeping spaces, to two, to one. Sam and Teal'c still slept to one side of the bed, Daniel and Jack on the other, but most mornings they would wake to find Sam and Daniel tangled together in the middle. It worked, in a strange way, for all of them.
2) Sam quickly became a favorite, with her light hair and her winning smile. Whenever the others would leave, they'd return to find her surrounded by children, and women, and usually a few men, all wanting to play with her hair and listen to her talk, even though they couldn't understand a word. She'd smile helplessly, and shrug, and then go back to explaining theoretical physics in a language that didn't exist yet.
3) Eventually Sam and Daniel would go to bed hours before Jack and Teal'c, and fall asleep to the low rumble of their voices.
4) Jack was killed last. He was forced to watch as staff weapons were aimed at Teal'c, then at an openly weeping Sam, then at himself. His eyes found Daniel at the last moment, and then he was gone.
5) Daniel lived, and wasn't quite sure why he bothered, except that he was the only one who would remember for them.