Katie on "The Bold and the Beautiful"
Katie (Heather Tom) warns Quinn (Rena Sofer, not pictured) that she’s still watching her on the April 20, 2017 episode of “The Bold and the Beautiful.” CBS

She was outraged that her sister refused to be the one to tell Eric the truth about Quinn and Ridge’s affair and decided to do something about it. Now, Katie will remind Quinn that she controls the fate of her marriage on the Thursday, April 20 episode of “The Bold and the Beautiful.”

Katie (Heather Tom) previously warned Quinn (Rena Sofer) on the CBS soap that if she went back on the promise she made Brooke (Katherine Kelly Lang) about staying away from Ridge (Thorsten Kaye), then she would quickly shatter Quinn’s world by telling Eric (John McCook) the truth. Furthermore, she also decided to have a little fun, and blackmailed Quinn into doing things for her whenever she asks.

Now, in a preview clip for the newest episode, Katie may witness Quinn and Ridge together once again. And even if their moment together is innocent, she will see a new opportunity to capitalize on her blackmail scheme, and will remind Quinn of the power she holds over her.

“I’m going to be watching you,” she says in the clip. “Try to go behind his back and I’ll be there. Whether it’s in his kitchen or at Forrester Creations.”

Read: Thomas Confronts Sally On “The Bold And The Beautiful”

Meanwhile, though everyone is keeping the truth from him, Eric is still curious about why Ridge and Brooke suddenly called off their wedding. He only knows it was Brooke who ended things, but has no idea it was because she saw Ridge and Quinn together. Now, still seeking answers, Eric will demand them from Ridge.

“What happened in Sydney Ridge?” He asks. “You and Brooke were supposed to get married. What happened? ”

“The Bold and the Beautiful” airs weekdays at 1:30 p.m. EDT on CBS.