By Natalie Abrams
August 14, 2017 at 06:11 PM EDT

Shay Mitchell has joined the cast of Lifetime’s adaptation of psychological thriller You from executive producers Greg Berlanti and Sera Gamble, EW has confirmed.

Based on former EW writer Caroline Kepnes’ best-selling novel of the same name, You is a 21st-century love story about an obsessive, brilliant bookstore manager named Joe Goldberg (Penn Badgley), who uses the hyper connectivity of today’s technology to make the woman of his dreams, an aspiring writer named Beck (Elizabeth Lail), fall in love with him.

Credit: Dimitrios Kambouris/Getty Images

The Pretty Little Liars star will play the series regular role of Peach Salinger, whose wealth and vast resources make her the controlling queen bee of Beck’s inner circle of privileged friends. She has her sights set on Joe in a way that feels oddly adversarial with Beck — and readers of the novel know why!

Mitchell joins the previously cast Badgley, Lail, Zach Cherry, and Luca Padovan.

Berlanti and Gamble will write and executive-produce You — which was given a 10-episode straight-to-series order in April — with Sarah Schechter, Leslie Morgenstein, and Gina Girolamo. It debuts in 2018.