Dexter: The British Invasion

In the season finale, Lila steals Dexter's GPS and arrives at the cabin where Doakes is imprisoned. Doakes tells her that Dexter is the butcher. She's shocked, but she tells Doakes that she's Dexter's soul mate. To prove it, she turns on the gas and the stove and leaves Doakes to get killed in the explosion, which he does. Dexter thinks he's in the clear, until he figures out Lila's involvement and decides to get rid of her. But she figures out his plan and to punish him, she brings Rita's kids to her apartment and when Dexter shows up to save them, she padlocks the door and sets the place on fire. Dexter helps the kids climb out the window and then wraps himself in a rug and busts through a burning wall to safety. They put an APB out on Lila even though Dexter's sure she's already gone. In the final scene, Lila's in France going through her mail when she sees a postcard from Miami with no address, only a picture of Doakes. Before she can react, Dexter injects her with a spinal epidural, carries her to the couch, and stabs her in the heart.