After suffering a traumatic brain injury from a car accident, Mary Dunne (Sarah Zanotti) is convinced that her husband, Grayson, has been replaced by an impostor. Mary receives phone calls from an unknown caller who claims to be the “real Grayson,” causing Mary to suspect that she’s living in a parallel universe with impostors who are gaslighting her and keeping her against her will. Tensions reach a breaking point when Mary finds out she is pregnant with the supposed impostor’s baby…