As much as I hate telemarketers, there are few calls that would distress me more than one from God assigning me to jury duty on Judgment Day. Frailty star and director Bill Paxton shares my metaphysical paranoia and is counting on this premise to scare horror aficionados everywhere. He nearly meets this goal, handicapped only slightly by the B-movie performance given by co-star Matthew McConaughey.

Paxton portrays a widowed father of two boys who gets that dreaded call from God. God's time-sensitive agenda calls for extermination of some local demons (rendered in mortal form as waitresses, police deputies, and other unfortunate townspeople). Dad's violent spiritual awakening takes on vivid, nearly campy proportions when he begins pontificating about being the "hand of God" and gaining the ability to lucidly differentiate between genuine demons and run-of-the-mill sociopaths. Hoping to set a morally upright example, he enlists his young sons to help capture the demons and gracelessly decapitate them in the family's woodshed.

Watching sweet-faced boys help their crazed Christian father hack up their neighbors is a deeply disturbing premise all by itself, and Paxton is smart enough to know that heavy-handed direction would have killed the script's impact. His light touch is matched perfectly with the classic cinematography of Bill Butler (Jaws, The Conversation), who shares his sensibility for favoring shadowy, suggestive cuts of the violence rather than gratuitous gore. The fearful confusion conveyed in natural performances by Matt O'Leary and Jeremy Sumpter as their father's unwilling accessories is also highly effective and deeply upsetting.

Unfortunately our suspension of disbelief is unceremoniously crushed by the melodramatic ego of Matthew McConaughey, who plays an older version of one of the boys telling the story to an oddly underwhelmed FBI agent. McConaughey's hammy presence and a couple of clichéd flashback sequences mar what could have been an excellent modern horror film, but the delicate steering by Paxton makes me hopeful about his future as a mature director.