Pretty Little Liars Season 4 Episode 17 Recap: A Total Gas >>Hollywood

WARNING: You may not want to watch Pretty Little Liars Season 4 Episode 17 if you are afraid of going to the dentist.

For what reason? Well… Hanna did some detective work, ended up with a teeth cleaning appointment in an attempt to determine who switched Ali's dental records - and ended up being gassed by A, who performed surgery and left a note between Hannah's teeth.

It read: I told you: dead girls can't smile, stop looking. Shiver.

Elsewhere on a fun episode, one that really picked up momentum in the second half?

• We learned that Mike and Mona are apparently a couple.
• We witnessed Ezra growing more and more suspicious, actually telling Aria that "people get what they deserve… eventually" and later sending someone a text about there being a "setback re: Alison."
• We saw Spencer inching closer to the truth about the shady teacher, going through one of Ali's diary entries and wondering about a date with a man at a bar by Hollis college. He ordered boysenberry pie and beer at the time. And later on this episode? She ran into Ezra ordering the same!
• Spencer also might be getting hooked on pills.
• And Emily nearly stabbed her dad with some scissors. PTSD, much?!?

At the end of the hour, we discovered that Tippy is still alive (yay!) and that A has a map of Cape May with Wilden's yacht marked on it. WTH? Why?!?