Cue the finger-to-the-lip shushing action, because this is important, guys.

The first list of characters expected to appear in the new Pretty Little Liars spin-off, titled The Perfectionists, has been revealed.

Joining Alison DiLaurentis (Sasha Pieterse) and Mona Vanderwaal (Janel Parrish) in the new Beacon Heights-set murder mystery series, per TV Line, will be: Caitlin Martell-Lewis, a political ingenue whose mother is a U.S. Senator and whose other mother is also a go-getter; Dylan Wright and Andrew, a couple whose passion for music and food makes them everyone's favorite 'ship already; Ava Jalali, subbing in as the fashionista du jour now that Hanna's gone; a smarmy rich guy named Nolan Hotchkiss; and a hot British scientist named Jeremy Beckett.

Casting for these characters is now reportedly underway, with their roles expected to become series regulars if and when the pilot is successful.

Many of these characters also appeared in author Sara Shepard's book of the same name, and if the show follows the plot lines of that story, there should be some very familiar dramatic elements to this PLL redux (like Caitlin striking up a relationship with Jeremy, after dating his brother, and some inappropriate teacher behavior towards young Ava).

Of course it's still MURDER that marks the backbone of Shepard's book, as the Perfectionists form their own little plan to do away with the town bully and, despite not going through with it, find out that he's died exactly as they planned and ... dun dun dun. Now, it's time for a simultaneous investigation and cover-up effort.

Some of the characters from the book have not made their way onto this list, like Julie — whose arc largely mirrors what Pretty Little Liars did with Ali's sister Charlotte DiLaurentis — but if the multiple-personalitied character isn't included in the small-screen take of the story, that'll only help to ensure its mysteriousness for even fans of Shepard's books.

The Perfectionist's tagline is, "Behind every Perfectionist is a secret, a lie and a needed alibi." Yep, sounds about right.