Dexter is greatly affected by the attack on Brother Sam. In the season 6 episode “Just Let Go” Dexter has to struggle with his darkest urges.
Dexter Season 6 Episode 6 – Episode Guide – Showtime
Dexter “Just Let Go” Summary
Dexter is caught up in a very personal case that awakens the needs of his Dark Passenger. (Poor Brother Sam aka Mos.) Meanwhile, Debra feels overwhelmed by her new Lieutenant duties, made all the more complicated when she finds out Quinn slept with a witness in the Doomsday case. (Looks like she’ll be utilizing more therapy, don’t you think?) Written by Jace Richdale, Directed by John Dahl.