Caught in a violent relationship with a brilliant and wealthy scientist, but obsessed with control, Cecilia Kass (Moss) manages to escape in the middle of the night and hides with her friend (Harriet Dyer from The InBetween). from childhood (Aldis Hodge, Straight Outta Compton) and his teenage daughter (Storm Reid, Euphoria).
But when his former partner (Oliver Jackson-Cohen of The Haunting of Hill House) commits suicide, and leaves much of his huge fortune left, Cecilia begins to suspect that his death is nothing more than a hoax. As she begins to face increasingly sinister coincidences that endanger the lives of her loved ones, Cecilia feels that her mental health is becoming more fragile because of her desperate efforts to prove to others that she is being harassed by others. a being that cannot be seen.