Dexter Morgan, Miami PD blood spatter analyst, is accustomed to seeing evil deeds – he occasionally enjoys committing them himself. Guided by his Dark Passenger – the voice that helps stalk his prey – he lives his outwardly normal life according to one simple rule: he kills only very bad people.
But everything changes when Dexter attends a gruesome double homicide. Dex realises he's dealing with someone a lot more sinister than he is, and it sends the Dark Passenger into hiding. And if the Dark Passenger is scared, it has to be serious...