It appears that the new baddie has finally made its presence known to the Liars. In fact, the slightest indication that it is on the prowl will send the girls in panic mode in the next episode of "Pretty Little Liars" season 6, which is titled "Do Not Disturb."

Aria believes that Sara Harvey is behind this new breed of terrors and threats. She has managed to convince Spencer to look for proof that Sara is, indeed, the person pulling the strings this time so they could halt her in her tracks before things go out of hand.

The search for the new enemy is on, and Spencer knows how difficult this will be.

"He could be anybody. Hiding in plain sight," she tells Caleb in the "Pretty Little Liars" season 6 teaser.

Team Sparia is on it but will the two outsmart the new big bad this time? Aria seems to be particularly invested in catching this new tormenter. In the previous episode, she has grown suspicious of her own father, who she remembered was so keen on eliminating Charlotte so the girls' troubles will end.

What's more is that one of Aria's father's iron golf clubs is missing. The same type of item was revealed to be the weapon used to take Charlotte's life. Could Aria's father be the perpetrator of the crime?

This week's "Pretty Little Liars" season 6 episode will also see Sara confronting Ali.

"When no one else was there for her, I was," the Sara tells Ali, referring to Charlotte. Teary-eyed, Sara emphasizes that only she knew Charlotte.

The teaser for the episode also shows that the new baddie has chosen his target – Emily. First, she finds a mysterious package at her door. In a different sequence in the clip, she slams the door.

In another scene in the "Pretty Little Liars" season 6 promo, Emily is seen donning a hospital gown, flinching, screaming and fighting as she asks "What did you do to me?"

Hanna, on the other hand, is seen throwing an envelope in a trash can, careful not be seen by anyone. The synopsis teases that she will team up with Caleb to get access to the security footages that will help them solve Charlotte's case.

"Pretty Little Liars" season 6, episode 15, "Do Not Disturb," airs Feb. 9 at 9 p.m. ET on Freeform.