Deb is moving out of the apartment, to give Dexter and Harrison more space. She’s staying with Quinn, but claims she isn’t actually moving in with him, because her clothes are not in any of the drawers. When she is packing up Dexter’s car, she finds a pair of Lumen’s sunglasses.
Dexter is now seeking Lance Robinson. Lance scours the Internet for young men, and then pushes their fantasies a little too far. He has so far killed four innocent young men. Dexter is prepared to get rid of him tonight. But, little does he know that Lumen is still in town. She puts on a disguise and heads out for the night, gun in hand.
Debra is heading up a surveillance operation at a local club that is a favorite hangout for the Fuentes brothers, who have been beheading victims. The Chief isn’t too happy about it and berates LaGuerta about it. She and Batista get into a huge fight, because he is convinced she brought the officer down last week to prevent herself from being associated with her husband’s negative situation.
Debra goes to visit Quinn, but he is busy getting information about her brother. Dexter just comes up as squeaky clean with a background check, making both of them even more suspicious of him.
Dexter gets ready to head out for the night. When Sonya, the nanny, tells Harrison to say goodbye to him, he says, “Die-die,” instead of “Bye-bye.” Dexter takes it as another sign: “Out of the mouths of babes!” But Nanny insists he said “Bye-bye.”
Dexter rents an RV and lures Lance to him. In the middle of setting up the kill room, Lumen calls in a panic because she has shot one of the guys who abused her. There is a lot of blood, and she doesn’t know what to do. Dexter dumps Lance in his trunk and takes off for Lumen, more in the interest of protecting himself. Lumen blames the kill on Dexter, saying she did it because he wouldn’t do it for her. But, major problem! The “body” is no longer there! He has run away. Dexter does what he does best – he follows the blood.
She tells Dexter about how she lured the victim out and brought him to a deserted warehouse. She is convinced that he was one of the men who raped her, based on the way he smelled and a “gut feeling” she had. This just infuriates Dexter even more, but he doesn’t want to get busted, so they keep hunting.
Someone calls in a possible homicide. Debra is ecstatic to take the case, because she is tired of watching Quinn flirt with other women at the club. Of course, Dexter also gets the text message about the crime scene and is expected to show up. Lumen is appalled to find out that Dexter works with the cops. Eventually, they find the man hiding in a grate. Dexter still is trying to find out how and why Lumen thinks the man is guilty. The man and Lumen get into a screaming match about whether or not they have met in the past. Dexter’s phone rings and it’s Sonya, with Harrison calling to his father. Lumen continues torturing him while he’s on the phone.
Dexter takes Lumen out of the room to yell at her some more. Suddenly they hear the man talking. She had dropped her phone. He has called someone and is saying, “She’s still alive! That last bitch is still alive!” Then he taunts her by saying, “They’re gonna find you!” Dexter snaps his neck and hands Lumen a hose so that she can clean up. Dexter takes off running to get his car to move the body. He calls Debra to say that he is on his way. He sends Lumen off to his old house, and Lance busts out of Dexter’s trunk. The tranquilizers have worn off. Dexter catches him, and strangles him with the cellophane wrap. Debra and everyone find Dexter, already parked at the body. Next to the body is Lance’s body. It looks like they killed each other in some sick sexual asphyxiation ritual.
Batista has left the bar with another woman. But instead of taking her home, as it looked, he brought her back to the station, because she has information on the Fuentes brothers. Batista uses it as a way to apologize to LaGuerta for their earlier fight.
Debra goes home to Quinn. She confesses that she has feelings for him. He confesses his feelings for her, in a cheesy typical love proclamation scene. And then they seal it with a kiss.
Dexter goes back to his house that he shared with Rita and looks for Lumen. The pictures of Rita are all over the table. He walks into the bathroom, and it’s like deja vu. Lumen is sitting in the tub where Rita died, with her eyes closed, and head cocked to one side. Luckily, she opens her eyes. He goes into the other room and she gets out of the tub. He goes to pull the plug for her and flashes back to the blood-covered bathroom.
Lumen starts talking to Dexter about his family. They both talk about how their lives had been planned out a little differently when they were younger. She confesses her past to him. She also confesses that she felt some peace tonight when her rapist died, and how she is scared that she is going to have to find the rest of them to keep feeling that sense of peace once it wears off. Dexter thinks to himself that he cannot avenge Rita’s death, but he can help Lumen avenge her rape. It ends with him asking her how many there were. He has a new partner in crime.
On the previews for next week, of course, he says he wants to work alone. What is going to happen with him working with a partner? The last time he tried that, in season three, it didn’t work out too well for him. How is Quinn’s new relationship with Debra going to affect his investigation into Dexter? All of Dexter’s problems always seem to magically fix themselves. How much longer until his luck runs out?