Dexter Morgan is a Miami crime scene investigator who is no stranger to evil deeds, particularly because he occasionally enjoys committing them himself. Guided by his dark Passenger - the voice inside him that helps him stalk his prey - Dexter lives an outwardly normal life adhering to one simple rule: he only kills very bad people.

Dexter slides through life undetected, working as a blood splatter analyst for the Miami Police Department, helping his fiancée raise her two adorable (if somewhat... unique) children, and always planning his next jaunt as Dexter the Dark Avenger under the light of the full moon.

But everything changes when Dexter is called to a gruesome double homicide. Dexter realizes he's dealing with someone far more sinister than he is, sending the Dark Passenger into hiding. And when something scares your friendly neighborhood serial killer, you know it's serious.

More used to inspiring fear than experiencing it, Dexter must investigate while simultaneously coping with his demanding family. If he's to save himself and those around him, Dexter must pose questions he's never dared to ask: Where does evil come from, and does it hide inside everyone?