This season on Riverdale, Jughead’s dad F.P. Jones has stepped back and let his son take control of the Southside Serpents, and he’s also getting hot and heavy with Betty’s mom Alice. He should be in a good place, right? Well, there’s still the matter of his wife… Jughead’s mom Gladys.

We haven’t met Gladys yet — she skipped town with Jughead’s sister Jellybean before the series began — but she’ll make her debut on the CW teen drama later this season, with Gina Gershon joining the cast to play her. And F.P. might not be all that thrilled to see her, series regular Skeet Ulrich admits. “I think there’s a lot to be worried about” with Gladys’ arrival, he hints. F.P. has just “started to get life by the horns a little bit and find a workable life with Jughead,” he notes, “and she’s the X-factor.” (Or did he mean ‘ex’ factor? Hmmm.)

F.P. and Gladys were estranged when she left town, and Ulrich says they don’t exactly fall into each other’s arms when she returns, either: “As [with] most toxic relationships, there’s someone that just sets you off. The reunion is certainly not what he would’ve wanted.” Gladys is actually “just like” F.P. was in Season 1, he adds, “just such a wildcard. You just don’t know what’s coming.”

Ulrich knew what was coming from Gershon, though: “I worked with Gina a long time ago. We did a Paul Schrader movie together called Touch [in 1997] and haven’t seen each other since. It’s great to work with her again. She’s really bringing something so unique and interesting [to the role].” (Additional reporting by Vlada Gelman)