Debra megpróbál megbékélni bátyjával és a kialakult helyzettel, miközben mindent elkövet, hogy eltussolja a gyilkosságot, aminek szemtanúja volt.

Miami Metro sets out to unearth new evidence on a claim from a local convict that he has new information regarding a 15-year-old crime spree; Debra tries to cure Dexter of his killer tendencies.

Dexter tries to bring Debra on board with his new target. While the Ukrainian mob seeks revenge for the killing of one of their own, Quinn grows close to a dancer at their strip club.

After capturing a deadly killer, things go awry for Miami Metro, sending Debra into a tailspin. In an effort to help his sister, Dexter enters into a dangerous game of cat and mouse, while the Ukrainian mob continues to seek revenge.

While trying to uncover why someone was killed on his boat, Dexter must out-maneuver a vengeful Isaak. New leads are brought to light on the Wayne Randall case by Hannah McKay, Randall's alluring former accomplice who Dexter discovers has a secret.

Egy helyi krimi író, Sal Price vonzódik Debrához, aki ezt kihasználva információkat szerez Hannah McKay-ről. Mindezek ellenére Dexter már tervezi, hogyan kapja el és vadássza le Hannah-t. Quin egy furcsa ajánlatot kap, míg Batista nyugdíjba akar vonulni és egy éttermet nyitni. Mindeközben, LaGuerta közel jár, hogy egy új bizonyítékot szerezzen a 'Öbölbeli Mészáros' ügyében.

Quinn falls back into his old ways as he makes some questionable choices to protect Nadia. Things heat up as Dexter and Hannah grow closer, but when Sal Price discovers the two are involved, he wants the exclusive story.

Fresh out of jail, Isaak renews his pursuit of Dexter while Quinn continues his power struggle with the Koshkas. Dexter tries to keep Debra in the dark about his relationship with Hannah, but a surprise visit from Astor, Cody and Harrison throws a wrench into his plans.

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.