Harry is trying to sleep, but he's having some bad dreams—understandable, of course, after everything.
Apparently abandoning the whole idea of sleep, he gets up and walks around. And then out of the house. Wait, where does he think he's going? Doesn't he know how unsafe "out of the house" is for him by now?
Ron chases him out and asks just what he's doing. Harry says he doesn't want anyone else dying for him.
Ron tries to reason with him, saying he doesn't think Harry should go without him and Hermione.
Harry ends up agreeing to come back in to the Burrow for now (after all, a wedding is about to take place) and Ron ponders where the Horcruxes are.