Dexter Morgan, a Miami crime scene investigator who is sometimes moved to commit murder himself--goaded by a reptilian voice he calls his Dark Passenger--gets a clue that something is very wrong when he is called to the scene of a double homicide at the university campus, only to have Dark Passenger go into hiding.

Dexter Morgan returns from his honeymoon in Paris and gets to work perfecting his disguise as the perfect husband, father, and investigator, and wondering if he will be able to put his homicidal tendencies to rest, but when a new serial killer is identified, Dexter is once again drawn into the battle for fitting justice.

Dexter, a serial killer who limits his victims to other killers, bides his time between murders by working as a blood splatter analyst for the Miami Police Department, and dating Rita, the single mother of two children, but he is faced with a challenge when a psychopath arrives in town and his sister, a newly-minted Miami detective, becomes involved in the case.

Dexter faces a murder charge for a crime he did not commit. His only chance for freedom lies with his brother, Brian, who has a dark plan to prove Dexter's innocence. But the stakes are deadly, and the epic showdown that lies in Dexter's path may lead, once and for all, to his demise.