After witnessing her brother kill Travis Marshall, Debra attempts to reconcile with Dexter while struggling to cover up their involvement with the murder.
To his surprise, an emergency with Harrison has Dexter leaning on Brother Sam for support as he questions the idea of faith.
When a local convict claims he has new information regarding a 15-year-old crime spree, Miami Metro sets out to unearth new evidence on the case. Debra attempts to cure Dexter of his killer tendencies.
Isaak renews his pursuit of Dexter after getting out of jail.
Dexter and the Homicide Division race against a lunar eclipse to catch the Doomsday Killers before their final gruesome act.