For months the team behind Longlegs has been releasing just enough unsettling details about the horror movie to tantalize viewers without revealing the full appearance of the massive celebrity in the cast, Nicolas Cage.

A viral billboard for the horror film advertised a phone number that when called plays a recording of Cage’s creepy voice. Other posts on social media have shared coded messages from the Zodiac-esque serial killer Longlegs played by Cage, never once showing his entire face.

According to a video shared on the film’s official social media accounts, writer-director Osgood Perkins also wanted to keep star Maika Monroe from seeing Cage fully decked out in costume and prosthetics until the cameras were rolling.

Monroe plays an FBI agent attempting to catch the serial killer. When she first laid eyes on him, according to the video, Monroe’s microphone picked up her heart rate increasing from 76 to 170 beats per minute.

Though horror movies might be terrifying for viewers, on set they’re notoriously less so — frightening characters are just co-workers, pools of blood are clearly fake, and unsettling darkness is neutralized through the presence of crew members and cameras.

Monroe told Yahoo Entertainment that the set wasn’t scary at all, but Perkins spent so much time building anticipation for the reveal of Cage’s character that it was “intense” for her in the moment.

“I think this was the first time I was genuinely [scared],” she said. “Nic Cage in insane prosthetics, unrecognizable as a monster … it was something I will never forget.”

Blair Underwood, who plays a more seasoned FBI agent, told Yahoo Entertainment that seeing Cage on the set was “terrifying and exciting at the same time.”

“Before you get to the Longlegs character, you’re looking at Nicolas Cage, who is this big movie star who works all the time and has a reputation of being avant-garde and pushing the envelope,” he said. “There’s an excitement that this is the titular character — the anchor of the film. His portrayal is terrifying.”

Even beyond Cage’s frightening character, the movie is unsettling throughout its entire run time — Perkins said it’s like a “horror movie mixtape” in the way it contains so many scary elements. It wasn’t entirely on purpose.

“I think there’s an impression with creation that there’s a real deliberate intent — that you know what you’re doing at all times. The fact is you just don’t,” Perkins told Yahoo Entertainment. “You’re guessing so much on everything. You’re relying on so many people’s contributions … and good luck.”

Alicia Witt plays the reclusive mother of Monroe’s character, who’s constantly asking her daughter if she still says her “prayers.” Witt told Yahoo Entertainment that she worked hard to keep herself emotionally safe while filming.

“When playing a role imbued with a lot of dark aspects and energies, it’s important for an actor to put a bit of protective energy around yourself when you dive into it,” she said. “It’s important to dive right back out of it … I didn’t bring it home with me at all. It was cathartic.”

Longlegs stands out from other recent horror releases because so little information about the plot has been revealed ahead of its release. Perkins gives total credit for that decision to the film’s distributor, Neon.

“I gave them the raw material and … they just loved the movie and felt like they didn’t want to reveal too much about it,” he said. “It’s uncommon for filmmakers to feel so good about their distributor.”

Underwood said the viral stunts used to promote the movie have been “brilliant.”

“I had my brother call and hear Longlegs’s voice, and he said, ‘Man, that sounds like a sick puppy,’” Underwood said. “I think it can be risky at first, until something has legs — pun intended — but since it has gone viral, people have grabbed onto it.”

Fans have praised the movie’s marketing on social media, calling it “so good I’m actually getting worried” and “the type of horror that makes you feel cursed.”

Longlegs is in theaters July 12.