Frailty is a non-gory horror film that achieves its chills by following the logic and impact of a man's delusion/obsession straight into depravity. Dad (we never learn his name) is a gentle man and loving father who's raising his sons alone after Mom died giving birth to the youngest son, Adam. The family's world flips upside down late one night when Dad rushes into the boys' room and tells them God has given him a vision. And what a vision  the entire family's job is to destroy demons, who, of course, are disguised in human form.<br /><br />Proceeding from this premise, the movie is unflinching in following it. Dad kidnaps people/demons whom God has told him to destroy, binds them, lays his hand on them to see a vision of their evil, then kills them  while making his young sons watch. Fenton, the older boy, is horrified, seeing only a father who's turned into a crazed murderer. Adam, the younger, is uncomfortable, but trusts that Dad is following God's will. Eventually, Dad takes his sons on missions to abduct the "demons" that God has put on Dad's list, and finally, invites them to fully participate in God's mission for the family.<br /><br />This is not, you understand, an abusive father. He loves his children. He is only following God's instructions: "This is our job now, son. We've got to do this." When Fenton, terrified and convinced his father has gone mad, says he'll report him to the police, his father explains, "If you do that, son, I'll die. The angel was clear on this." The pressure that the children are under is unbearable and tragic, and warps their entire lives.(1) The movie's structure is similar to the one used in The Usual Suspects: a story in flashback, told in a police station to a FBI agent. The moody lighting, the stormy weather, and the eerie calm in the present day add to the menace of the backstory. I wanted to believe the unfolding horror was just a story, until I remembered the real-life parallel of Andrea Yates, who believed she was possessed by Satan and could save her children by drowning them. Even then, I wanted to believe that I was watching a human tragedy, rather than a story of divine retribution.<br /><br />The movie gave me no such comfort, though, as it gave strong clues at the end about the veracity of Dad's vision. And this, as much as some plot holes, posed a problem for me. Regardless of the accuracy of Dad's visions, regardless of the evil that his victims may have committed, where does anyone derive the authority to act as an angel of death? (1) Roger Ebert review, 4/12/02