Deb notices some poisonous gas in the air and notifies Homeland Security. Deb sends Quinn and others to investigate Beth's apartment. Just before they arrive, Travis sends Beth to Miami Metro on a suicide mission. She is specifically instructed to kill Deb. Beth gets into Miami Metro, but Deb is out in the field. Quinn shows up at Beth's and finds Batista tied up. Dexter realizes that Beth is Adam's wife. Dexter goes after Beth just as she releases the gas. Dexter kills her, but inhales some of the gas.
Homeland Security investigates and they back off after concluding that Adam and Beth are not terrorists. Deb goes to see her therapist who calls her out on her feelings about Dexter. The therapist says that Deb needs to be truthful in her feelings towards him and that she needs to figure out whether or not she wants to be with him.
Dexter goes and creates a trap to lure in Travis. In response to Dexter's creation, Travis paints Dexter as a devil before going after him. Just as Travis arrives, the gas Dexter inhaled earlier hits him, leaving him physically incapacitated. Travis sets the boat Dexter is in on fire and it explodes. Unknown to Travis, Dexter escapes just in time.