The "Pretty Little Liars" spin-off "The Perfectionists" is still in its early stages and the pilot has yet to be filmed, but showrunner Marlene King is already spilling beans on what fans should expect from the new show. One thing they can be sure of is that the new series will be chock-full of mysteries.

Speaking to TV Line, King said "Perfectionists" is "tonally" similar to "Pretty Little Liars." "There is a big mystery, and there is a murder, and there are some characters who are a fractured group at the beginning of our story, and through a murder they become friends," she explained. "So it's similar in that regard, but it's a whole new mystery, a whole new murder."

Based on Sara Shepard's novel series of the same name, "Perfectionists" centers on five high school students -- Ava, Caitlin, Mackenzie, Julie, and Parker -- who are bonded together by their mutual hatred of a bully named Nolan Hotchkiss. In the books, the group jokingly comes up with a plan to murder the boy, and when he ends up dead the way they planned, they become embroiled in a mystery.

King suggested she is going for a killer vibe and has made sure the real-life locale she chooses for the fictional Beacon Heights matches that feel.

"The show takes place in the Pacific Northwest, and we wanted to be true to that, to Sara's book," she said. "Plus, I really liked the way Rosewood became a character on Pretty Little Liars, [so I wanted to] have a new character, a new town. Portland and the Pacific Northwest are so moody and creepy to begin with. That's going to be a lot of fun to explore."

King failed to mention how the spin-off is connected to the parent show, only confirming Alison (Sasha Pieterse) and Mona's (Janel Parrish) involvement in the first episode. They may not be the only ones from the mothership to grace "The Perfectionists," though. More familiar faces are said to be dropping by the new town of terror, just "not in the pilot."