Dexter: Season 4, Episode 12

4 - 12: The Getaway

As the noose tightens, Arthur warns Dexter to back off. But Dexter will do anything to stop Arthur from eluding him, even if that means putting himself on the wrong side of the law. Rita acknowledges the rocky relationship she and Dexter share, but reaffirms her support. Meanwhile, Batista and LaGuerta face the consequences of their actions and now that they are married agree to move in together. Debra finally learns that Dexter is the Ice-Truck Killer's brother and tells Dexter. She then tells him he is the only constant truly good thing in her life and that she loves him. At the culmination of the episode, Dexter finally captures and kills Arthur, but then goes home to find Rita dead... apparently killed by Arthur hours earlier in the same manner as the other Trinity bathtub victims, and Harrison, alive, sitting in a pool of Rita's blood