Reeling from Debra witnessing Dexter kill Travis Marshall, brother and sister attempt to reconcile while struggling to cover up their involvement with the murder. Meanwhile, Detective Mike Anderson has an unfortunate run-in, Quinn and Batista begin to make amends, and LaGuerta finds evidence that causes her to re-think the closed Bay Harbor Butcher Case, which could mean trouble for Dexter-- and Debra...
Much to his own surprise, an emergency with Harrison has Dexter leaning on Brother Sam for support as he questions the idea of faith. But when Dexter is confronted with Gellar and Travis' next awful tableau, he is forced to ask if faith, in the wrong hands, is deadly.
Mike is outnumbered by his wife and daughters when they all agree that baby proofing the house is a good idea. But soon Vanessa has second thoughts when she finds herself home by herself babysitting Boyd and can't release the toilet seat's complicated childproof latch. Meanwhile, Mike thinks it's time for Mandy to earn her own money and gets her a job delivering pizzas -- without first consulting Vanessa.
When a local convict claims he has new information regarding a fifteen-year-old crime spree, Miami Metro sets out to unearth new evidence on the case. While Debra attempts to cure Dexter of his killer tendencies, the Mike Anderson case leads to the Ukrainian mob, and a vengeful Louis won't stop meddling with Dexter's life.
Dexter and the Homicide Division race against a lunar eclipse to catch the Doomsday Killers before their final gruesome act. Debra struggles with, but finally faces up to, a new emotional reality.
