It has been a year since Paige and Nathan Decker tragically lost their teenage son Zach to an overdose. Nathan and daughter Addie have slowly been putting their lives back together. Paige, however, just can't seem to let go. She is still consumed by grief, withdrawn, and unable to work. In order to supplement Paige's lost income, the family decides to rent out their spare bedroom. Surprisingly, life starts to look up for Paige once their charming new tenant, Brandon Wilson, enters the picture. A student at the local university, Brandon eerily resembles everything that Zach stood for in the family, and he brings Paige out of her shell. At first, Nathan and Addie are thrilled to see Paige acting more like her old self, but as Brandon insinuates himself further into the family, they start to see a darker, and more dangerous side of their tenant. Soon, Addie uncovers a secret about Brandon that is about to shake the Deckers to their core. Can a family in crisis hold themselves together in the face of an evil genius?