In the Season 6 premiere, Dexter attends his high school reunion to hunt a former Prom King; an investigation into a faith-based murder causes Dexter to ask some spiritual questions; Debra becomes an unexpected hero.
To solve a macabre murder, Homicide consults Brother Sam, a minister whom Dexter recognizes as a fellow killer with an even better cover than his own; now a local hero, Debra is surprised by two life-changing proposals.
Dexter is confronted with a glimpse of his own possible future when a serial killer from his past reappears; Debra is uncomfortable in her new job; Travis and Gellar prepare a new twisted tableau.
Disturbing events cause Dexter to lean on Brother Sam during a crisis of faith, while Debra gives her first press conference on the new religiously motivated serial killer.
The search for the Doomsday Killers takes Dexter in a new direction; Batista and Quinn pay a visit to the university where Professor Gellar taught; due to departmental regulations following the shooting, Debra is forced to begin therapy.
Dexter becomes caught up in a very personal case that awakens the needs of his Dark Passenger; Debra feels overwhelmed by her new duties, and discovers a disturbing secret about Quinn.
Dexter teams up with a fellow Dark Passenger when he takes a road trip to Nebraska; Debra deals with the complications of her promotion as she leads the Doomsday investigation.
Dexter uses lessons he learned from Brother Sam to follow up on some new Doomsday leads; Debra butts heads with LaGuerta over the case of a dead call girl.
Dexter tries to figure out the Doomsday Killers' next victim; Debra has a strong reaction to a crime scene, leading her to realize that she leans too heavily on her brother.
Dexter finds that in order to catch the Doomsday Killers, he must create a macabre tableau of his own; Debra's battle with LaGuerta boils over, and her therapist makes an unnerving suggestion.
In the Season 6 finale, Dexter and Homicide race a solar eclipse to catch the Doomsday Killers before their final gruesome act; Debra struggles with a new emotional reality.
