S06E12 This Is the Way the World Ends

Stuck in the ocean miles from shore, Dexter is rescued by an old boat carrying illegal immigrants to the US. He even manages to render them a service. Once ashore, he heads home hoping to figure out where and when Travis will stage his last tableau. Travis has holed up in a small house and has killed the occupants. While he's away, the police show up and Dexter has something of a surprise waiting for him. Dexter makes it to son Harrison's school recital only to have Travis take the child. Meanwhile, Debra has a plan to catch Travis and gets LaGuerta's support for her plan. Debra also comes to terms with her feelings for Dexter. In his final confrontation with Travis, Dexter has him tied down on his execution table. Someone walks in just as he's committing the deed.

S06E11 Talk to the Hand

Dexter finds himself at the yacht where Travis and his accomplices were preparing the next tableau, Wormwood". They quickly realize that Travis is planning a gas attack. Worried that Batista has not been seen since the previous day, Quinn sets off to find him. Travis meanwhile sends Beth Dorsey to Miami Metro homicide with a canister of deadly gas and orders her to meet with Lt. Morgan. Deb has dinner with Deputy Chief Matthews and discusses the case of the dead call girl. The next day Deb realizes that Laguerta is very adept at office politics.

S06E10 Ricochet Rabbit

Now realizing the error he has made, Dexter redoubles his efforts to track down the doomsday killer and eliminate him. He plants evidence in the church to keep the police off the scent and sets out to find DDK. He manages to track down Holly, the woman Travis freed, but too late. From the evidence at the crime scene, Dexter believes he knows what DDK will strike with next, though he has no idea where. With Quinn hung over and not at work, Batista sets off to interview a person of interest which may have major ramifications for him. Meanwhile, Deb goes through the evidence from the dead call girl case and now knows who was with her and who Laguerta is protecting. Louis the crime lab intern is more than a little deflated when Dexter slams his new computer game.

S06E09 Get Gellar

Having rescued Travis at the church, Dexter now tries to figure out what the next tableau will be. With Travis having agreed to help him, Dexter gets him a room in a hotel to keep him safe. A clue from one of the paintings eventually leads Dexter to a Professor Casey, an avowed atheist. He tries to warn Casey about what may happen but the professor brushes him off, claiming to get threats all of the time. Unfortunately, the doomsday killer strikes again. When Travis disappears, Dexter traces him to the church. Dexter finds him alive but also makes a startling discovery. Meanwhile Batista takes Quinn to task when he fails to show up for work and apparently left his phone and gun behind in someone's car when he left the strip club. Debra decides to reopen the case of the dead call girl despite Capt. Laguerta's objections.

S06E08 Sin of Omission

Dexter returns to Miami after his road trip to Nebraska and get a frosty reception from Debra who has been under pressure to get results in the doomsday killer case. He does his best to make amends, but doesn't share what he knows about Travis and Professor Gellar. Thanks to Masuka's intern Louis, the police now have a list of 200 of Gellar's former students living in the Miami area and the team fans out to interview them all. It doesn't stop the Doomsday Killer from striking again with a new tableau: the Whore of Babylon. Meanwhile Capt. Laguerta takes a particular interest in the death of a high class prostitute and seems desperate to have the case ruled an accidental death.

S06E07 Nebraska

Having avenged Brother Sam's death, Dexter gets some bad news from Deb - it appears the Trinity Killer has returned to kill his wife and daughter, leaving his son Jonah as the only survivor. Dexter knows that Trinity is lying in pieces at the bottom of the ocean and immediately suspects that Jonah may have taken over where his father left off. He sets off for Nebraska to confront Jonah accompanied by someone from his past. When he confirms Jonah's role in the deaths, Dexter clearly has a choice to make. Back in Miami, the team gets a significant lead when they locate the girl Travis released. But with Dexter unavailable, the squad are missing a key expert to analyze what they've found. Travis stays with his sister and seemingly ends his relationship with Gellar. Captain Laguerta embarrasses Debra at a meeting.

S06E06 Just Let Go

As Dexter is following Travis in the hope of finding Professor Geller, he learns of Brother Sam's shooting. He races to the hospital to learn Sam is unconscious. He sets out to find the killer and is quite certain who the culprit might be. During a brief lucid period, Sam asks him not to avenge his death. Deb tells Batista to get Professor Porter down to Miami for further questioning but realizes the whole case is in jeopardy when she learns Quinn spent the night with her. At the police psychologists suggestion, Deb decides to throw a house warming party. Meanwhile, Travis seems to be having trouble following Geller's orders and must decide what to do with the young woman they've kidnapped.

S06E05 The Angel of Death

Dexter runs background checks on Travis and discovers that he was a former student of Gellar. Batista and Quinn go to the university where Gellar used to teach.

S06E04 Horse of a Different Color

Dexter is in awe of the latest display from the Doomsday killer: the Four Horsemen of the Apocalypse made up of mannequins and human body parts. Testing confirms that the human parts all came from the same body. Deb Morgan, in her capacity as the new Lieutenant in homicide, holds her first press conference which she concludes did not go well. She is certainly very blunt. Meanwhile, Geller is unhappy with Travis' decision to go on a date with a pretty waitress. There's a price to pay for that. Dexter has a family crisis when Harrison has a burst appendix. Back in the lab, Masuka finally learns what Ryan has been up to.