standing for "Doomsday Killer") and the main antagonist of Season 6. He is in fact directly involved in these murders, with mentor Professor James Gellar passing on his legacy to his student, making him believe that every murder committed is justified. However, his empathic nature leads to him to come in conflict with Gellar's demands. Travis has a sister Lisa (Molly Parker), a teacher, who tells her students that he is a talented artist. As the season progresses, particularly after his encounter with Dexter, Travis begins to feel guilty about the suffering of their victims despite Gellar's insistence that the victims are sinners and their deaths are necessary. When told to brand their "Whore of Babylon" he relents to her suffering and releases her, which leads to the police looking for an accomplice. He also leaves Gellar and returns to live with his sister, though Gellar continues to stalk him. When the police department begin researching possible accomplices, his sister answers Debra's house call. Dexter also attempts to recruit Travis before the police find him, which Travis refuses in fear of Gellar. Deciding he has waited long enough, Gellar brands Lisa as the Whore and kidnaps Travis, chaining him at their base. Dexter tracks down their headquarters, but Gellar escapes. Travis pledges allegiance to Dexter in vengeance. Dexter stashes Travis away while he hunts for Gellar; Gellar somehow finds him and paints a message to repent on the bathroom wall, which Travis tells Dexter is a message to meet. On arrival, Gellar reprimands Travis and allows him to return, though he knocks him unconscious. When Dexter enters, he attempts to locate Gellar but instead finds Gellar's frozen long-dead body. Dexter concludes that Travis has been seeing hallucinations of Gellar and has a mental disorder. This is later confirmed when Travis's prescription for anti-psychotic medication is found in the church. When faced with the body of Gellar, Travis resolves to "finish what they started", seeking new acolytes in the Dorseys to complete the tableau of "Wormwood", a poison gas attack. He also is determined to locate Holly Benson, the first Whore, and kills her. While hiding out with Beth Dorsey, Travis detains a lone Sergeant Batista, and sends Beth with Wormwood to attack Miami Metro, which Dexter narrowly averts. While falling for a trap Dexter sets, the side-effects of the gas's components disorients Dexter which allows Travis to defeat him, completing