With the help of his newfound friend Brother Sam, Dexter wonders if there is light within him to counter the darkness, while the search for the Doomsday Killers takes him 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.

Miami Metro gets closer to Gellar and Travis thanks to the new intern. Meanwhile Dexter deals with faces from the past. Travis tries to move on from Gellar.