7. Debra will Arrest Dexter
This option is fairly likely, especially considering that not only is this really her duty and she should have done this from the very start (although I am not sure I would have in her position) and considering she very almost did this anyway. Predicting the high probability that Dexter will kill again, if Debra were to find this out, I believe she would have too much of a difficult time with her conscious to simply allow Dexter to continue to kill "innocent" people and will have no other choice but to arrest him for his crimes. This will be a horribly difficult thing for Debra to have to do, but she really will have no other real choice. Also, if you ask us, if one of the members of Miami Metro really should arrest Dexter, and considering Dexter's arrest is one of the most likely possibilities, it would make a lot more sense if it was his sister. There is still something about this option that seems a little odd to me, which suggests that maybe this won't actually happen. I almost feel like if Debra knew it was her duty to arrest Dexter, she could even likely quit the Miami Metro to make sure that it never comes down to that, and she isn't breaking her all important codes. But the thing about Debra which makes her polar opposite to Dexter is that she has always been highly moral and has always done what is good and best. Considering simply by helping Dexter she is breaking so many laws, eventually this might take its toll forcing her to either leave the force (and even perhaps leave the country) or arrest her brother. In the last episode she did express a great fear in handing Dexter over to the police because she can't bear the thought of Dexter spending his life in prison or worse, being put to death (very likely considering Dexter has single handedly murdered more people than any person in history- probably) but this is when she thinks Dexter is trying to be good and to not kill. At this point that is kind of the case, although he has already within a short amount of days already drugged his sister and sneaked out of the house where she has been keeping him locked away. If and when Dexter starts killing again, Debra may change her mind and come to grow disgusted with her brother.