Dexter finds himself unable to kill his victims; Debra returns to work.
Dexter remains on the trail of a dangerous new victim; Debra loses control on the job; an FBI agent arrives in Miami.
Dexter pursues a slick liar; Rita forces Dexter into a 12-step program.
Dexter's Narcotics Anonymous sponsor threatens Rita; Dexter tries to throw the FBI agent off his trail.
Dexter discovers that the man who murdered his mother is still alive.
A copycat killer starts a vigilante serial-murder spree; Dexter sets out to stop the imposter.
A manifest throws the task force into chaos; Lila's influence takes its toll on Dexter's personal life.
Lila attaches herself to Dexter after the fire, which makes him uncomfortable.
Dexter tries to distance himself from Lila; Lundy's manhunt makes Dexter nervous.
Doakes tracks Dexter to his latest kill; the Miami Metro Police Department starts closing in on the Bay Harbor butcher.
Dexter finds himself dodging bullets; Lila tries to blackmail him.