Simon and Robyn are a young married couple whose life is going just as planned until a chance encounter with an acquaintance from Simon's high school sends their world into a harrowing tailspin. Simon doesn't recognize Gordo at first but after a series of uninvited encounters and mysterious gifts prove troubling a horrifying secret from the past is uncovered after more than 20 years. As Robyn learns the unsettling truth about what happened between Simon and Gordo she starts to question: how well do we really know the people closest to us and are past bygones ever really bygones?