Twenty years ago, gregarious Lorelei and mousy Holly became fast friends as students in the same college psychology seminar. Taught by an expert in control and human behavior, the two students also grew close to their charismatic professor. But in one twisted moment of gaslighting, their friendship flamed out and Lorelei’s once-promising future fell apart.

Flashforward, Holly has everything Lorelei ever wanted, while Lorelei is a lonely cat lady. Now, Holly is even up for an award at a Woman of the Year ceremony, and Lorelei finally has the perfect opportunity to get the revenge she’s wanted for years. But she’s not the only person who has been obsessively following Holly’s career—and when someone winds up dead, Lorelei realizes she may be in danger, too.