Tom felt quite confident of his safety, but physically he felt awful. He had a hangover, the terrible, jumpy kind that made him stop halfway in everything he began doing, even stop halfway in brushing his teeth to go and see if his train really left at ten-thirty or at ten-forty-five. It left at ten-thirty.
He's really becoming a dab hand at this(show spoiler)
if all he suffers from is the hangover from the various cocktails of the night before.