Dexter and the Homicide Division race against a lunar eclipse to catch the Doomsday Killers before their final gruesome act.
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.
A surprise visit from Hannah's father puts Dexter on alert, and the phantom arsonist's crimes become more gruesome.
As Christmas approaches, Dexter tries to balance his life with Hannah and his relationship with Debra. Unbeknown to Dexter, Debra follows up on what could be an incriminating tip.
As LaGuerta closes in on Dexter's secret, Dexter struggles to protect himself, Debra and the life he's built.