Dexter is drawn into a precarious situation; Batista discovers an interesting lead; Quinn gets information about Dexter from a questionable source.

Dexter is called to investigate a horrifying crime scene; the Santa Muerte case leads to a violent standoff between Debra and the Santa Muerte killers.

Brother Sam, a minister with a criminal history, is brought in by the homicide department to help solve a macabre murder, but Dexter sees him for what he really is, and it's definitely not a man of God. Elsewhere, Debra's sudden hero status elicits a pair of surprising proposals.

Much to his own surprise, an emergency with Harrison and a new tableau from Gellar and Travis has Dexter leaning on Brother Sam and an unexpected winged messenger for support as he questions the idea of faith; with proof of a religiously motivated killer, Homicide hunts for a zealot, with Debra giving her first official press conference.

Dexter receives help from an unexpected source while hunting the Doomsday Killers and staying one step ahead of Homicide; Debra discovers something new about herself in therapy.

Dexter finds that in order to catch the Doomsday Killers, he must create a macabre tableau of his own; Debra's battle with LaGuerta over the case of the dead call girl boils over, and her therapist makes an unnerving suggestion.

As Dexter scrambles to track down Isaak, a power struggle erupts among the Koshka Brotherhood, which could prove to Dexter's advantage. Meanwhile, Miami Dade tries to smoke out the Phantom Arsonist.

Dexter is unnerved when Hannah's father pays him a surprise visit; the Phantom Arsonist's crimes become more vicious; and Quinn defends Nadia's honor and finds himself in a volatile situation. Meanwhile; LaGuerta asks a former superior for help on the Bay Harbor Butcher case.

It's Christmas time, and Debra learns it may be better to receive when she gets a tip from Hannah's father... one that could lead to incriminating Dexter in a crime. Meanwhile, Dexter discovers that the man behind his mother's death has been released from prison.

Dexter must protect himself when LaGuerta closes in on his secret.