We may have learned plenty of secrets from last night's (Jan. 21) episode of 'Pretty Little Liars,' but we were left with even more questions. Such is the nature of the beast.

In this promo for episode 4x17, 'Bite You Tongue,' two possible members of the A Team appear to join forces and A hides a message inside one of the Liars. Literally.

Proceed with caution, this post is bursting with possible spoilers.

Mona makes her return to the show and guess who she's meeting up with? None other than A suspect number one: Ezra. It looks like they will share a scene or two together which is fine by us.

Meanwhile, Hanna and Spencer are incredibly busy investigating the re-disappearance of Ali; and Emily is once again trapped in a seemingly dangerous situation, this time inside their school.

That photo that A burned of Emily inside a locker is starting to make much more sense now.

And just when you didn't think things could get any creepier, Spencer finds a note that appears to be hidden inside Hanna's tooth. Yup, inside. We don't know how that's possible either -- unless A got a job as a dental assistant, which is entirely possible.

You can catch 'Bite Your Tongue' next Tuesday on ABC Family at 8PM ET.