After helping her clean up the murder of her husband, Dexter sticks by Hannah's side to help her flee, even taking her on a road trip with him to track down Zach.
And there was a ton of drama in store.
Take a look at what went down on Dexter's "Are We There Yet?"
Zach the Serial Killer?: Following his neighbor Cassie's murder, Dexter covers up for Zach after he runs the blood under Cassie's nails and Zach's stats pop up. Zach appears to have fled, so Dexter heads out on a road trip with Hannah to track him down.
And when he does, what he finds is extraordinarily creepy.
Dexter discovers Zach's empty hotel room, which Zach has essentially recreated (or tried to recreate) to look like Dexter's killing style, picking up a knife set just like Dexter's and covering up the entire room in plastic.
But, when Zach busts in the room soon after and Dexter confronts him with a knife, it becomes clear that Zach wasn't the one who bludgeoned Cassie to death.
Zach said he's been going after a guy he went to high school with who strangled a girl, and that at the time of the murder, he was busy stalking him.
And he had proof-time stamped photos he had taken of Sean that happened at the same time of Cassie's murder.
And then there was also Sean's dead body in the back of his car.
So, who killed Cassie and framed Zach?
Hiding Hannah: During Dexter and Hannah's road trip to find Zach, Hannah and Dexter can't seem to hide that they're both still smitten with each other. As Dexter hands Hannah a new passport to help her start a new life overseas, they end up kissing and then naked in Hannah's bed.
The next day when it's time for Hannah to fly out on a helicopter, Dexter pops up and asks her to stay.
Shocking Twist: After spending the night making love to Hannah, Dexter comes home to find Zach sitting lifeless in his desk chair with a chunk of his brain cut out.
Which means the Brain Surgeon is still out there.
But, who is it?!
Don't forget to catch the next episode of Dexter Sunday at 9 p.m. EST. on Showtime.