Daniel doesn't sleep for what feels like hours; he realizes belatedly that he didn't even take off his shoes before simply lying down, still too used to sleeping in boots and BDUs and ready to be shaken awake to take off a moment's notice. And he's still tense from the everything they've had to collectively deal with for the past...ever.

After a while he resorts to the meditative sort of deep breathing, which takes its time but eventually does the trick. And it certainly helps that Seth is right there, away from cells and interrogation rooms and rebels. Seth's safe, that's what's important, and that's the thought that finally allows for him to sleep.