Sierra Barter begins investigating her step-grandfather Jim by reaching out to family members, some of whom she had not spoken to in years. By interviewing Jim's ex-wives, children, and stepchildren, Sierra begins to put together a horrifying image of the man her step-grandfather was and the terror that he inflicted on his own family.

Jim Mordecai was a revered teacher to most, but to others, he was a monster. Sierra looks deep within herself and questions if Jim’s crimes may have escalated. A curious family heirloom launches Sierra down a rabbit hole where a series of unsolved murders has her asking if Jim could be the killer.

Sierra’s uncle shares a disturbing story further implicating Jim and a private investigator urges Sierra to find evidence. After Sierra searches through family storage, she learns the truth about a night that changed her family forever, and in turn, takes her investigation into a different direction.

With the help of cutting edge technology, Sierra is able to build a DNA profile of Jim. Armed with the evidence she needs, Sierra hands her files over to law enforcement hoping to convince them to investigate and help her family step out from Jim’s shadow.