The season follows Dexter Morgan, who is forced to deal with his past when he comes across Dr. Evelyn Vogel, an expert on psychiatry who returns to Miami. Nicknamed the "Psychopath Whisperer", she claims to have structured the code for him alongside Harry. This season also deals with a new serial killer in Miami that removes pieces of the victims' brains, and with Debra who is trying to deal with what she has done in the past season.