Dexter attempts to vet Zach Hamilton in order to see if he's a killer. Quinn also tracks Hamilton's moves believing the young man to be responsible for the Rivera death. Vogel wants Dexter to teach Hamilton Harry's Code but Dexter is reluctant.

Deb and Elway team up to prove that Elway's sister's boyfriend is a cheater and Elway proves his intentions where Deb is concerned are more than strictly professional. 

Batista decides to promote Miller instead of Quinn.

Dexter and Deb get a shocking visit.