Darkly Dreaming Dexter is a 2004 crime novel by Jeff Lindsay, the first in his Dexter series. It introduces Dexter Morgan, a blood-spatter analyst for the Miami Metro Police Department who moonlights as a serial killer, targeting only other murderers according to a strict moral code. The novel is narrated in Dexter's darkly humorous, detached voice, revealing his inner struggle with his 'Dark Passenger' and his relationships with his sister Deborah and his girlfriend Rita. The story follows Dexter as he investigates a series of elaborately staged murders that seem to be calling out to him personally, leading him to question his own nature and the possibility of a companion.
Published by Doubleday, the book received critical acclaim for its original premise and voice, winning the 2005 Dilys Award and being nominated for a Macavity Award. It spawned a series of sequels, including Dearly Devoted Dexter and Dexter in the Dark, and established Dexter Morgan as a memorable antihero in contemporary crime fiction. The novel's unique blend of horror, humor, and psychological insight made it a bestseller and led to a major television adaptation that expanded the character's reach worldwide.