Dexter is obsessed with getting the Trinity Killer himself, especially after Arthur has tracked him to Metro Homicide and learns his real identity. Dexter realizes the threat to his family and with the older stepchildren off with their grandparents, he convinces Rita to take Harrison to the Keys where he will join them later for a weekend honeymoon. His first attempt to take care of Arthur goes awry when as a result of a traffic accident, he finds himself in jail for leaving the scene. His second attempt is more successful, but his obsession to kill Arthur comes with a price. Meanwhile, no one can quite understand why Debra is still at work given what happened to Christine Hill, but when the FBI takes over the Trinity Killer case, she refocuses on learning more about her father and his relationship with his confidential informants. Debra finally learns about how her father came to adopt Dexter. Also, Laguerta and Batista now have to decide what to do next in their relationship.