"Darkly Dreaming Dexter" follows the exploits if a young man, Dexter Morgan in Miami. Dexter is a swell guy - he has a nice job (blood spatter analyst for the Miami Metro Dade police dpt), a nice family (foster sister Deborah Morgan) a circle of friends (his "lab geek" forensics co-workers) and a girlfriend (Rita). The only thing Dexter doesn't have is a soul - at night he exists quite apart from his carefully crafted persona, stalking his prey.
Dexter Morgan is a serial killer, but one with a twist - unlike most serial killers, Dexter never plies his craft on the innocents. Instead, he hunts murderers, rapists, pedophiles and/or some combination of the three.
Dexter was raised by the Morgan family, and his foster father, Harry Morgan, a police detective for the aforementioned Metro Dade dpt, spotted Dexter's hobby early on. He trained Dexter to dispense justice upon those criminals that "slip through the net", and to cover his tracks - as only a cop can teach a killer.
Now, many years later, Dexter's life runs smoothly - until a string of elegant murders turns his life upside down. A killer is loose in Miami, who is as crafty, original and fond of his trade as Dex himself. To top this off, the killer actually seems to have an insight into Dexter's private life. As the novel progresses the killer seems to be reaching out to Dexter through his "art" - and Dexter himself begins getting disturbing dreams in which he himself is at every crime scene, witnesses the murder and the following ritual. Dexter begins to doubt his sanity, and suspects that he is responsible for the murders.
The novel also follows Dexter's relationship with his sister Deborah, and his girlfriend Rita. Though Dexter seems to feel nothing at all for Rita and only stays around because of his need for a disguise, he does care about Rita's two children from her disastrous former marriage.
One thing that is fascinating about this novel is Dexter's narration - he is portrayed as a killer, with no remorse or morals, other than the ones Harry had imprinted on him. He has no feelings for the people surrounding him (other than Harry), no understanding of the motives an drives of normal people, and no apparent desire to understand. Dexter's duplicity is described in jarring detail, and the dark humor of the novel does not take the edge of the description of someone who seems entirely alien.
This book presents a novel concept of a serial killer with a moral compass. But it does not slip into cliches- the serial killer is still cruel, soulless and dispassionate. Dexter does not change into a likable person, he is not really good and kind. Because of the excellent characterization of the novel's hero this book deserves praise. A very morbid and thought-provoking read.