Tune into ABC Family for the next episode of "Pretty Little Liars" where the Liars find out that they have tracking devices implanted in them!

The promo video on YouTube for next week's episode, titled "No Stone Unturned," shows that the Liars are petrified when they find out that Charles knows their every move. Did he plant the device in them when they were trapped in his Dollhouse? Is he even "A" anymore?

In the last episode "She's No Angel" Aria, Emily, Hanna and Spencer started to think that "A" is actually a woman, according to iDigitalTimes.

They jotted down Lesli Stone as their first suspect. In the promo video the Liars revealed that they think she was the one who implanted the tracking devices in them.

Yet, showrunner Marlene King said Charles is definitely "A." Also, the summer finale is titled "Game Over, Charles" implying that he will finally be caught. The big question now is, Why is he doing all of this?

King says that Charles' face will be revealed in the finale as well. So far, viewers have only seen him in a balaclava mask, although there have been no obvious clues about him in recent episodes.

King revealed that fans would also learn who hit Bethany Young in the head with a shovel.

In previous shows, they learned that Young, who was originally identified as Alison when "A" switched their dental records, was buried alive. Viewers thought the blow to the head was what killed her but later found out that she died from asphyxiation.

Meanwhile, Charles is coming home soon, according to Unreality TV. Spoilers reveal that Charles is coming home for his birthday while Hanna and Spencer thinks it's the perfect chance to catch him.

Beware of Charles homecoming because it could just be another trap.

Tune into ABC Family Tuesday nights at 8 p.m. EST to see what happens next on "Pretty Little Liars."

Watch the video: