Dexter Spoilers
Spoilers
In the Dexter books he finds out Cody is developing some of the murderous tendencies for blood thirst as Dexter did at that young age, after seeing this Dexter begins to train Cody, this or Astor going through training being that she is older in the TV show and an overall more likely candidate could be a theme that is present in the fourth Season of Dexter.
It is likely that if this were to occur the show would need to jump ahead a couple of years if it were to get violent because the children are so young, this would be done after some of the more current problems such as blood on his new wife’s wedding dress are solved.
Along with the children developing the same murderous tendencies as Dexter an even more likely plot would be Debra discovering that Dexter is the Ice Truck Killer’s brother. This would most likely lead to the discovery of what he hides so deeply along with a load of conflict between his sister, wife, and other close friends.
I actually believe that it is very likely she will find out about Dexter’s connection with Brian, the Ice Truck Killer, at which point she will have to put the pieces together from the very start and discover what is really going on. The clues are there, from Harry cheating on his wife, her mother to the picture left behind on her desk, judging from her personality, which is dominated by persistence, this is a very likely event. She will find out about the other mother, his murderous brother, and from there it can only get more interesting, the possibilities seem endless. Though there are some secrets that ONLY Dexter is capable of sharing I don’t see Debra having a problem finding him out and leading to a confrontation this season.
I believe that Debra is too nice of a person to simply let it go if she just suddenly discovers the truth about Dexter, however if it something that occurs to her slowly, over a number of episodes, as well as finding out that Harry knew about what was going on and helped him with controlling it in a way that innocent people are protected, she may be more open to coming to a consensus with Dexter.
Much of the plot will be based on how Dexter reacts to the situation, one thing is for certain though, expect Dexter not to make many new friends and possibly lose some old ones in the process.