Dexter is saddled with an unwanted conspirator; Dexter worries about how Rita's death will affect Harrison; Deb works alone; Quinn enlists an old friend's help.

Dexter catches a mysterious woman who may have witnessed him in the act of killing a killer; Deb has a frightening run-in with a murder suspect in the Santa Muerte homicides; and Quinn uncovers more striking similarities between Kyle Butler and Dexter Morgan.

Dexter hires a nanny; Debra is annoyed with her new partner; Quinn continues to investigate Rita's murder.

Dexter tries to focus on the children and fight his dark urges; Debra ends up on Quinn's doorstep.