Gossip Girl star cast in the spin-off for Pretty Little Liars

She'll be bringing the Upper East Side to Beacon Heights.

It was announced late last year that Pretty Little Liars would be getting a spin-off series.

Freeform handed out a pilot order for Pretty Little Liars: The Perfectionists - based on the Sara Shepard book of the same name - and confirmed that two original stars of the series would be back.

Most of the details of the plot are being kept under wraps, but we've recently gotten our first look at the trio of 'perfectionists': Ava (Sofia Carson), Caitlin (Sydney Park) and Dylan (Eli Brown).

The Pretty Little Liars Facebook page confirmed most of the new additions on Friday, alongside the fact that another familiar face will be joining the series.

Gossip Girl's Kelly Rutherford, who played Lily van der Woodsen on the series, has been cast as Claire Hotchkiss, the "icy matriarch" of the family.

The description reads:

"The icy matriarch of the Hotchkiss family, Claire (along with her husband) is the founder of Hotchkiss Industries and the respected Beacon Heights University. "Claire believes perfection is attainable and is the person who pulls the strings behind the scenes to get what she wants"

The series will also star Sasha Pieterse and Janel Parrish, who will be reprising their roles as Alison DiLaurentis and Mona Vanderwaal.

But rather than returning to Rosewood, the series will be taking place in the town of Beacon Heights - which, from the sounds of things, is even more dramatic than Rosewood.

The show’s description reads:

"Everything about the town of Beacon Heights seems perfect, from their top-tier college to their overachieving residents. “But nothing in Beacon Heights is as it appears to be. “The stress of needing to be perfect leads to the town’s first murder. “Behind every Perfectionist is a secret, a lie and a needed alibi."