The origin of the "dark passenger" was explored and with out getting in to too many details, it turned out to be one of the many spawns of an ancient body jumping evil demon that existed since before the age of the dinosaurs and was worshiped through out the ages as a god. In the book, it was hunting its own decedents which caused Dexter's passenger (the demon's spawn) to go in to hiding and left him to his own devises. In addition to trying to figure out what was spooking his old buddy and how to stop it, he also had to deal with cody's and ester's newly awakened passengers and mold and shape them in to productive functioning psychopaths like himself, as harry did with him.
I didn't really like that whole supernatural aspect of it. People are more then capable of great evil all on their own. there was no need to explain why he does what he does. some people are just wired wrong. There is no need to blame it on demons. this is why i wish they will stay away from it on the show and wont try to explain what makes him tick.
***Edited By: juno on 12/23/2009 12:58:52 PM*** Reason: sp
The essence of hypocrisy is the tendency to make an exception of oneself.