JOE HILL'S 2010 NOVEL Horns has an intricate story that peels back to reveal a dark coming-of-age fantasy about a twentysomething man named Ig whose childhood love is brutally killed in the woods, at which point everyone in town decides he's the murderer. The old Kafka rub: Ig wakes up one day with devil horns sprouting from his forehead that inspire everyone to say and do bad, bad things. The satanic horns are a ham-fisted plot device, which, thanks to Hill's deft storytelling, are immediately forgiven—I wish the same could be said about the movie.

The adaptation of Horns, directed by Alexandre Aja (Piranha 3D, 2006's The Hills Have Eyes), stars Daniel Radcliffe as the unfortunate Ig, whose ever-present goaty protrusions are constant reminders that this all rings a little silly without the inner thoughts and backgrounds of the novel's characters. Okay, but how's the film on its own merits? Well, Radcliffe is definitely likeable as a disheveled, bedeviled man whose broken heart is outweighed only by his need to avenge the death of Merrin (Juno Temple), surrounded as he is by friends and family confessing their terrible, dark desires at him. But Horns' locust plague of tonal problems defeat any charming qualities Harry Potter might have—no matter how much fun it is to watch him commune with snakes again.

Ig's story is ostensibly an origin story of a supernatural avenger—and sadly, that also means it's saddled with Merrin's grisly "Women in Refrigerators"-style murder, her character merely a defiled vision of purity. Then there's the film's wobbly swerving from "comedy" (haha, look at those closeted cops get it on under the horns' influence!) to squicky punishment scenes. Top it all off with cringe-inducing soundtrack choices and a desperately winking screenplay ("Are you horny?" asks Merrin to Ig), and Horns proves the devil is in the details.