After being forced into retirement and the sudden death of his wife, Richard is determined to live under his own terms; Neil, his estranged slacker son, sees instead an opportunity to have him declared unfit to live by himself so that he can get sell the house and keep the money. Their plans are thwarted when Edey, a homeless woman with a history of mental illness, sneaks into Richard's house and manages to conceal her presence. As Edey becomes increasingly obsessed with filling the void left by Richard's wife while protecting him from Neil's schemes, father and son are unwittingly forced to escalate their conflict, with violent consequences. Saturnalia is based on the shocking true story of a homeless woman who managed to live for a full year in a man's house by hiding in an unused closet.