The supporting cast of characters is deeper than just these two women. The show also explores the lives of several detectives within the police department, as well as the politics of the department. These additions help make the world Dexter lives in seem more real, and add a depth to the show that is beneficial.
Much of the wit in the show seems to stem from the fact that Dexter is just this regular old, average guy, someone with all the trappings of a normal, ordinary life, he just happens to be a serial killer. His love of blood spatter at murder scenes gives some of his "differences" away, but the show really works the dichotomy of average-Dexter versus killer-Dexter very well.
The mystery of the "Ice Truck Killer" is also a good hook for the 12-episode season. Once the killer is revealed (and the audience ought to know who it is about two episodes before anyone on the show figures it out), the story becomes no less interesting. Again here the show works the "two sides of the same coin" premise wonderfully, exploring the "good" serial killer, Dexter, with the "bad" serial killer, "Ice Truck."
The first season DVD also comes with a handful of special features. There are a couple of featurettes, one on an actual case in which blood-spatter analysis played a crucial role, and two episodes of Showtime's Brotherhood TV series. When used on a computer there are also downloads available, including an episode of The Tudors and two chapters of a new Dexter novel. There are also audio commentaries for some episodes.
Dexter's new season starts on Showtime September 30, but the Season One DVD set is available for purchase now, and it is a darkly good time.