The film had its world premiere at the 2014 Toronto International Film Festival, and was released theatrically in the United States on October 31, 2014.
Ignatius "Ig" Perrish becomes the prime suspect when his girlfriend Merrin is raped and murdered. Despite his declarations of innocence, he is shunned by the community. He stays with his parents and brother Terry, hiding from the press. After a vigil led by Merrin's father, who believes Ig to be guilty, Ig drinks heavily, urinates over Merrin's memorial, and wakes up with a pair of horns protruding from his head.
While at his doctor to try and remove his horns, Ig, under anesthesia, dreams of his childhood, when he first met Merrin. A young Ig and his friends play with cherry bombs; Ig risks a dangerous dare to win a cherry bomb, and nearly drowns, but is saved by Lee, his childhood friend and now-lawyer. He later trades the cherry bomb with Lee in exchange for fixing Merrin's broken necklace; however, Lee loses two fingers when the cherry bomb goes off accidentally. Ig and Merrin bond over the fixed necklace and fall in love, frequenting a treehouse in the woods together.
The horns are revealed to force people around Ig to tell him their darkest secrets and desires, which, under Ig's bidding, they act upon. Ig goes to visit his parents, but under the power of the horns his mother reveals that she doesn't want him as her son, while his father tells him that he is worthless without Merrin and that a friend of his helped him burn down the lab where DNA tests were being conducted. Ig goes to a bar, where he goads the reporters into a brawl and attempts to find evidence that he didn't kill Merrin. Several people confess their deepest secrets, and the bartender burns down the building.
From one of the confessions Ig also learns that the new witness for the case is from the diner where Merrin broke up with him the night she died. Ig finds the waitress, and discovers that she has been fabricating her stories to become famous. When Ig talks to Terry, he learns that Terry had driven Merrin from the diner the night she died. When he touches Terry, Ig sees what happened that night: Merrin left the car en route to her home and ran into the woods; Terry passed out in the car, and woke up the next morning with a bloody rock in his hand, finding Merrin dead under the treehouse. Afraid that he would be implicated, he fled. Infuriated, Ig assaults Terry until he is arrested by Eric Hannity, a police officer and another childhood friend. The next morning Ig is released from jail with Lee's help, discovering that Lee had been wearing Merrin's cross necklace and as a result couldn't see Ig's horns.
Ig realizes that snakes are following him wherever he goes, and uses them to exact vengeance against the waitress. He also gets Eric to act on his feelings for his fellow police partner (who reciprocates his feelings) and forces Terry to overdose on drugs, causing Terry to be tormented with memories of Merrin's death. Ig meets Lee by the docks and pulls off Merrin's necklace; exposed to the horns, Lee falls under their influence, admitting he killed Merrin. In flashbacks, it is shown that Lee was also in love with Merrin and was deeply jealous of Ig throughout their childhood. Lee followed Merrin into the woods, thinking that she had broken up with Ig to be with him, and in a jealous rage raped her, killed her with a rock, planted it on Terry, and stole her necklace. In the ensuing confrontation, Lee overpowers him and lights him on fire in his car, causing Ig to drive into the bay, claiming that Ig confessed to the crime and committed suicide. In reality, with the power of the horns, Ig survives, horrifically burned and disfigured.
Merrin's father, who now believes Ig's innocence, gives Ig the key to Merrin's lock box. When Ig puts on Merrin's cross, his body is restored and his horns disappear. In the box, he finds a note from Merrin that explains that she knew he was going to propose, but she was dying from cancer and didn't want him to suffer, so she pushed him away under the pretense of loving someone else.
Ig confronts Lee, who does not remember their earlier fight, and leads him into the woods where Merrin was killed. Meanwhile, Eric and Terry arrive to arrest Lee. Lee confesses to the murder, but then gleefully kills Eric and injures Terry. Ig tears off the necklace, sprouting a pair of wings and bursting into flame, transforming into a demonic monster. Despite Lee mortally wounding him, Ig impales Lee on one of his horns and telepathically forces a snake down Lee's throat, killing him. Stating that his vengeance was all-consuming, Ig dies from his injuries and his smoldering corpse turns to hardened ash, and he appears to be reunited with Merrin in the afterlife.Daniel Radcliffe as Ignatius "Ig" Perrish, a 26-year-old man who wakes up after a drunken night to find two protrusions growing from his forehead, which give him the power to compel people to unravel their deepest secrets. Radcliffe stated, "It’s a very, very different type of part than anything I've done before", adding that the role was "deeply emotional and also incredibly outrageous in some ways".Mitchell Kummen as young Ig
Max Minghella as Lee Tourneau, Ig's childhood best friend and now lawyer.
Dylan Schmid as young Lee
Joe Anderson as Terry Perrish, Ig's alcoholic, drug-addicted older brother, who is also a talented musician.
Jared Ager-Foster as young Terry
Juno Temple as Merrin Williams, Ig's late girlfriend, who is raped and murdered.Sabrina Carpenter as young Merrin
Kelli Garner as Glenna
Laine MacNeil as young Glenna
James Remar as Derrick Perrish
Kathleen Quinlan as Lydia Perrish
Heather Graham as Veronica, The Waitress
David Morse as Dale Williams
Alex Zahara as Dr. Renald
Kendra Anderson as Delilah
Michael Adamthwaite as Eric Hannity, Ig's gay friend, who is now a cop.
Erik McNamee as young Eric
Desiree Zurowski as Radio reporter
Shia LaBeouf was originally set to play the lead, but was later replaced by Radcliffe.
The band seen backing up Joe Anderson's character on lead trumpet is The Brass Action from Vancouver, British Columbia. The scene features the band's song, "The Devil Down Below".
Explaining his initial interest in the project, Alexandre Aja said "After reading Joe Hill's cult book, I couldn't resist temptation to dive into the devilish underworld and reinvent a universal myth".
Principal photography started late September 2012, in British Columbia. The filming took place in Vancouver, Mission, Surrey and Squamish, completing shooting in December 2012.
The world premiere was held at the 2013 Toronto International Film Festival,
The film was released in North America and the United Kingdom on October 31, 2014, however the movie was also made available via digital download on iTunes as of October 6, 2014.
Horns grossed a total of $3,875,442 worldwide in 31 days of release.
The film's North American distribution rights were acquired by Dimension Films and RADiUS-TWC. Anchor Bay Entertainment released the film on January 13, 2015 on DVD and Blu Ray.
Horns received mixed reviews from critics. Review aggregator Rotten Tomatoes gives a 41% approval rating based on 112 reviews with an average rating of 5.2/10. The consensus says "Horns is a bit of a tonal jumble, but it offers enough thoughtful horror-comedy—and strong work from Daniel Radcliffe—to hook genre enthusiasts."
John DeFore of The Hollywood Reporter gave a positive review of the film, remarking, "While this all begins as a kind of supernatural black comedy ... the tone grows darker with each revelation".
Joe Hill, who wrote the novel the film is based on, praised Radcliffe's performance, calling it a "wrenching, vulnerable, emotionally naked performance that isn’t like anything he’s ever done on screen before. He is such a wonderful Ig Perrish".
The Guardian scored the film two out of five stars, calling it "a Dogma-style mash-up of grim comedy and religious satire". Eric Kohn of IndieWire wrote, "Predominantly a failure of tone, "Horns" has plenty of admirable traits and yet dooms itself from the outset. It's an admirable conceit stuffed into far less subtle material". Peter Debruge of Variety sensed that the film "benefits from the helmer's twisted sensibility, but suffers from a case of overall silliness". Jonathan Weichsel of MoreHorror.com stated that "The cast is all around terrific, especially Daniel Radcliffe who is nothing short of phenomenal, and the set pieces are entertaining in that wild, over the top way that only horror can pull off effectively.".