"That Night, A Forest Grew"
No.1 A written manifesto from the "Bay Harbor Butcher" sends the Special Task Force in charge of capturing the killer into chaos but agent Lundy was able to track down the plan of Dexter and made conclusion that the "Bay Harbor Butcher" has Law Enforcement Background meaning he is one of them.

No.2 The relationship between Dexter and Lila became more deeper Lila was very afraid that Dexter would come back to Rita. Agent Lundy and Debra was on thier way to a love affair. Maybe.

No.3 Sgt. Doakes was out of the job. When he crossed the line, Dexter was so mad, using his intelligence, Dexter made a good setup to Sgt. Lundy and then after that, he was out!.