Dexter gets the news from Deb that Brother Sam has been shot. He has to abandon his current task, stalking and killing Travis, to take care of this, and he is not happy. Hezeroesin on Leo Hernandez, the guy who replaced someone Dexter had killed. Leo ends up getting shot and killed in a standoff with cops.
As time goes by, Dexter becomes less and less convinced of Leo's guilt. The real shooter is the guy that Dexter saw Brother Sam baptize, Nick. To Dexter's surprise, Sam asks Dexter to forgive the guy, instead of pursue him. On his deathbed, Sam tells Dexter that that he knows his darkness, but he also sees his light.
Dexter decides to try and convince Nick to turn himself in. He does not and Dexter ends up drowning him in the lake where he got baptized. Dexter is thenconfrontedby his (dead) brother Brian Moser. Dexter has an internal conflict - he wants to protect the ones he loves, but he knows he cannot change.
Deb's new position has been affecting her relationship with others in Miami Metro. Deb admits that she regrets how things ended with her and Quinn. Quinn asks her if she ever loved him, and she does not answer.
A chick Quinn was getting close to is called into questioning. Deb was not to happy to her some of the things she was telling her, and Quinn blames it on Deb's jealousy. Quinn shows up drunk at Deb's housewarming party where he ends up hitting on Jaime that lands him a punch in the face from Batista.