Frailty asks not what extremes a religious zealot might go to, but what extremes a normally non-zealous person would go to if they suddenly believed God Himself had communicated with them. It's a daunting question, and, as the focal point of the film, is handled with terror as shown through the eyes of some children who experience such a situation first-hand.
The film stars, and is directed by, Bill Paxton, who makes his debut behind the camera. The project screams "Take me seriously, please!" but is nevertheless an accomplished turn for the actor, who builds atmosphere and sustains it through dark cinematography and a creepy screenplay. Paxton plays Mr. Meiks, or "Dad", a man who cares about his sons, but begins to lose his grip on reality after he tells them he has been visited by an angel. The angel has a list of seven people who Dad is told must be killed for their sins. The elder son, Fenton (Matthew O'Leary in a mature performance), knows that murder is wrong, but is torn by the love he feels for his disturbed father. The younger son, Adam (Jeremy Sumpter), is of course more susceptible to the rhetoric. The trio follows out the instructions, but the gory actions clearly take their psychological tolls on all three. After a grisly point in this extended flashback, the movie continues in the present with Matthew McConaughey explaining his father's killings to an FBI agent in the present day.
Director Paxton tries to keep Dad's visions an ambiguous interpretation open to interpretation, but in presenting several death scenes without supernatural embellishment, he clearly tips his hand. While Dad is a character who implicitly believes his victims have been taken over by demons, the leap is too great for the viewer to make. An attempt late in the picture to legitimize the action of putting one's hand on a person's head -- almost in a TV evangelist style -- seems ripped out of the clairvoyant-but-suspenseful screenwriter's handbook.
The dialogue is natural in Frailty, and certainly the performances, including Powers Boothe as Agent Doyle, are accomplished, but the bookends are hokey and cheat the hard-hitting questions posed in the middle of the movie. The modern Hollywood thriller is clearly running out of steam -- not in terms of interesting concepts, but by the sheer number of movies that are now opting for conclusions with a twist of some kind. Ignore the coy attempt at a surprise ending with Frailty, and it works better as a chilling and competent character study.