Dexter shows up at his 20th high-school reunion with the intention of confronting the former prom king. Elsewhere, an investigation into a heinous murder with religious overtones leads Dexter to ponder spiritual matters and wonder about his son's legacy. And an unexpected situation results in Debra becoming a hero.

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.

Dexter is confronted with a sobering glimpse of his own potential future when a serial killer from his past makes a startling reappearance; Debra is uncomfortable in her new job; Travis struggles to keep his mentor happy, as he and Gellar prepare a new twisted tableau, ensuring Debra's next task will be a daunting one.

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.