Young Dexter Morgan struggles to keep his urges in check while navigating life with his father, Harry, and sister, high-school senior Deb. After Harry has a health scare, Dexter realizes it may finally be time to fulfill his destiny.
Dexter targets a retired mob hitman (who may still be killing), as Harry works the gruesome murder case of a ten-year-old boy; Deb sneaks into a nightclub with Sofia and meets an exciting new friend.
After a kill goes wrong, Dexter is grounded by Harry; Deb deepens her relationship with Gio, and bonds with her brother on the anniversary of their mother's death.
Miami Metro is shaken by a kidnapping that hits close to home, as Dexter sets his sights on a killer that slipped through the cracks of the justice system. But first, Dexter must survive a double date with Deb and her new boyfriend.
Dexter needs to find a new hiding place after his most recent dumping ground is blown. Harry and LaGuerta pitch a controversial theory to Spencer, as the hunt for a missing child continues.
Deb sneaks away for a trip with her mysterious boyfriend; Dexter is tasked with finding her; Harry and LaGuerta travel to Tampa to look into a potential serial killer on the loose; Miami Metro closes in on suspects in the child kidnapping.
After a failed SWAT operation, Dexter pursues a child abductor. Deb shadows her father at work, gaining new perspective on Miami Metro. Harry investigates a serial killer but withholds his suspicions from LaGuerta.
Dexter races to find the missing kidnapped child before it's too late. Deb visits her godfather in the hospital and rethinks her future. Harry comes face-to-face with a serial killer... leading to a shocking result. Season finale.
