TORONTO - Joe Hill has got to be feeling good tonight.

Before the world premiere of Alexandre Aja's "Horns," adapted from Hill's second novel, several members of the cast joined the author onstage to introduce the movie. Seeing Hill, there's always that jolt at first where I'm struck my how much he looks like his father at that age. At this point, Stephen King is probably numb to the idea of movies based on his work. For Hill, though, this is brand-new territory, and based on how closely the film hews to his book, he must be pleased.

Unfortunately, screenwriter Keith Bunin's  fidelity to the novel means that the book's problems are now the movie's problems, and while I liked much of "Horns," I do think it has a few major issues. If you didn't read the novel, the set-up is pretty simple. Ig Perrish (Daniel Radcliffe) and Merrin Williams (Juno Temple) have been in love since they were kids, which makes it all the more difficult to understand what happened when Merrin's dead body is discovered, her head bashed open. Immediately, Ig becomes the only suspect in the case, and he finds himself having to cope with his own crippling grief even as the media and the law fall on him like a ton of bricks.

Ig maintains that he did not kill Merrin, even as everyone else believes he did, including his own family. Even worse, her father (played by the always great David Morse) is convinced that Ig is guilty, and he seems prepared to kill Ig if he ever gets the chance. Ig retreats into a fog of alcohol until he wakes up, hungover, startled to find that he apparently has horns growing out of his head.

Tone is terrifically difficult in a film like this, because the potential for it to be silly is massive. Aja seemed to be locked in a sort of career stutter ever since he broke through with "High Tension," so I was surprised how much he seems to have grown as a filmmaker. I'm not even sure I'd call "Horns" a horror film. It's like a supernatural version of "Gone Girl," and yet, there is some very, very dark comedy in the film as well, and by keeping it dark instead of letting the humor undercut the severity of the situation, Aja has made what has to be his most commercial film so far, and it may change the way producers and studios think about him. Part of the credit also goes to Daniel Radcliffe, who captures a perfectly balanced blend of fury and confusion as he tries to figure out what's happened to him.

One thing that is clear is that the horns have power over anyone he's talking to, and they seem powerless to stop themselves from confessing their darkest desires to him, then enacting them, without any thought of consequence. They also become incredibly open to suggestion, a dangerous ability to give to someone who is as heartsick and damaged as Ig is. Those sequences perfectly illustrate how well Aja balances tone, because people end up doing some outrageous things, and I think it's meant to make you laugh so that later, when Aja starts playing everything more seriously, it packs much more of a punch.

The supporting cast in the film all seem perfectly cast. James Remar and Kathleen Quinlan play Ig's parents, and when they see the horns, their frankness scares Ig. He decides to use whatever these horns are to track down and punish Merrill's killer, and little by little, he begins to figure out how to use the horns instead of worrying about how to get rid of them. The film makes great use of Vancouver forests in place of Seattle, where the film is set, and it's far more lush than anything Aja's made up to this point. Then again, it was shot by the great Frederick Elmes, whose use of color and texture in "Blue Velvet" is still a high watermark for lush but wretched beauty.

Heather Graham shows up in a small but pivotal role, and architectural marvel Kelli Garner manages to elicit real sympathy in just a few scenes. Joe Anderson is very good as Ig's big brother, and Max Minghella, playing a lifelong friend of Ig's, seems determined to clear Ig's name, giving Minghella a very active and personal stake in what happens. Across the board, these are some of the very best performances in any of Aja's films, and they are all good enough to make me overlook some of the things that bother me about the movie and the novel.

When you're making a film like this, where you introduce some sort of supernatural element into the everyday, you need to establish some rules. Otherwise, anything could happen at any time, and it doesn't seem truly motivated. I also think they squander Ig's ability to look into the hearts of other people, forcing them to look at themselves in the process. There's a point in the film where it seems they've thrown that idea away, and it's a shame. It's a great one.

"Horns" does not currently have a US distributor, and while I have my own reservations about the material, I think a smart distributor could make "Horns" into a big win for all involved. Here's hoping this is just the beginning of Joe Hill's work being adapted to the screen, and that whatever comes next honors Hill's work so resolutely.