The Real Housewives of Orange County are turning up the tension in a way no one expected — with a polygraph test. In an exclusive sneak peek of the Aug. 28 Bravo episode, the cast sits down for nerve-wracking lie detector sessions aimed at uncovering the truth behind a shocking claim: that Katie Ginelli allegedly told a blogger Tamra Judge once “roofied” Gretchen Rossi back in season four. With accusations flying, the women are forced to prove who can really be trusted.

Even those not directly tied to the drama aren’t safe from the hot seat. Heather Dubrow admits that the machine makes her second-guess herself, while Shannon Beador nearly spirals into a panic. “I think that I could possibly make myself so nervous that I’m going to screw it up,” she confesses, before being grilled with hilarious but biting questions like whether she thinks she’s better looking than some castmates.

But all eyes are on Katie, whose test could make or break the fractured group. Despite her nerves, the proctor assures her that anxiety won’t affect the results. Meanwhile, the rest of the Housewives speculate and snark from the sidelines, fueling even more tension. Viewers can watch the drama unfold when The Real Housewives of Orange County airs Thursday at 8 p.m. on Bravo.