Pretty Little Liars spin-off adds Walking Dead and Gossip Girl stars 

‘s Kelly Rutherford, and newcomer Eli Brown will round out the cast for

, which already stars Sofia Carson alongside

Park will play Caitlin, who’s described as someone who’s “smart, driven and thrives under pressure,” according to a press release. Caitlin is “the perfect daughters of two perfect mothers” and has “set her sights on following in her mother’s Senatorial footsteps.”

Then there’s Brown, whose Dylan rounds out the trio of “perfectionists” alongside Caitlin and Carson’s Ava. Dylan is described as a gifted cellist who “grew up feeling judged in his small hometown and now feels the need to be the best in all of his endeavors. He is deeply committed to his two passions, his music and his boyfriend, Andrew.”

As for Rutherford, she will play Claire Hotchkiss, the matriarch of the Hotchkiss family and, along with her husband, the founder of Hotchkiss Industries and Beacon Heights University. According to the release, “Claire believes perfection is attainable and is the person who pulls the strings behind the scenes to get what she wants.”

‘s Hayley Erin in an unnamed mystery role.

, which is based on the popular book series by Sara Shepard, is yet to get a premiere date.