Believe it or not, the inspiration for the film all started with an episode of The Simpsons.

Obsession hit theaters just a few weeks ago and quickly turned into one of the most talked-about movies of the moment.

The horror sensation has already earned $148 million at the global box office.

If the film left you wanting to learn more about how it came together, here are 17 fascinating behind-the-scenes details that make the experience even more interesting.

 Warning: Major spoilers for Obsession ahead. 

1. Director Curry Barker built his career on YouTube before making the film.

At just 26 years old, Barker was already known as a comedian and the creator behind the YouTube channel that’s a bad idea before stepping into feature filmmaking.

2. The entire production wrapped in only 26 days.

Despite its ambitious horror sequences, the movie was completed on an incredibly tight shooting schedule of less than a month.

3. A classic The Simpsons episode sparked the original concept.

Barker revealed that the idea came while watching “Treehouse of Horror II,” the second Halloween special from The Simpsons. In the episode, Bart uses a cursed monkey’s paw that grants wishes with disastrous consequences.

“I still remember sitting on my couch and suddenly thinking, ‘Oh my god,’” Barker told Triple J. “I immediately wrote it down, and from there I just kept expanding the idea.”

4. His mother helped create the One Wish Willow.

While searching for an alternative to the familiar monkey’s paw, Barker struggled to find a wish-granting object that felt original.

“I didn’t want to use the monkey’s paw because everyone already knows it,” he explained to IndieWire. After considering wishing wells, shooting stars, and wishbones, none of them felt right.

His mother, a graphic designer, eventually helped design the One Wish Willow, giving it a timeless, retro appearance that looked as though it could have existed for decades.

5. Barker’s father contributed one of the movie’s creepiest moments.

The unsettling Hansel-and-Gretel-inspired story Nikki reads during the party was actually written by Barker’s father, who had recently started exploring screenwriting.

6. Wildfires destroyed one of the filming locations before reshoots could happen.

Barker hoped to return to the house used for the party scenes, but the property was sadly lost during the Los Angeles fires before additional filming could take place.

7. Inde Navarrette had to learn how to scream for horror films.

Before taking on Nikki, Navarrette admitted she had never learned proper horror screaming techniques.

She explained that she and Barker spent considerable time practicing everything from vocal delivery to movement so her performance would feel authentic.

8. Michael Johnston landed Bear without a traditional audition.

Instead of auditioning immediately, Johnston first received the screenplay from his representatives.

He intended to read only a few pages but became so engrossed that he finished the script in one sitting and even canceled his plans. After meeting Barker and participating in chemistry reads with several actresses, he ultimately secured the role opposite Inde Navarrette.

9. Mia Goth served as a major inspiration for Nikki.

Navarrette looked closely at Mia Goth’s performances in X, Pearl, and MaXXXine, admiring the way Goth always portrayed her characters as human before emphasizing their instability.

She wanted audiences to empathize with Nikki’s emotional struggles rather than simply view her as “crazy.”

10. The duct-taped door was much simpler than it appeared.

To create Bear’s heavily taped door, the art department designed a removable sheet covered in duct tape instead of attaching every strip individually.

Only the outer edges were secured to the wall, making the setup much easier to remove between takes.

11. Nikki’s unsettling movements were created without a choreographer.

Rather than hiring a movement coach, Barker and Navarrette developed Nikki’s eerie physical performance together.

Drawing on her dance background, Navarrette collaborated closely with the director to perfect every unusual gesture.

12. Barker secretly appears in the movie.

The director provided the voice of the One Wish Willow phone operator.

He later revealed he recorded the dialogue in his room during post-production while editing the film.

13. Makeup—not prosthetics—created Nikki’s haunting appearance.

Makeup artist Kate Oja relied solely on strategic highlights and shadows inspired by the uncanny valley effect to make Nikki appear even more unsettling in dark scenes.

14. One violent sequence had to be shortened for theaters.

The scene in which Nikki attacks Sarah with a brick originally continued much longer.

To secure a wider theatrical release, Barker trimmed both the impact and some of the gruesome aftermath, although he believes the emotional intensity remained intact.

Navarrette added that disturbing sounds and additional details following the attack were removed because they pushed the limits of the intended rating.

15. An emotional confession was cut from the car scene.

One version of the conversation revealed that Sarah admitted Nikki had secretly developed feelings for Bear.

Although Barker found the revelation heartbreaking, it was ultimately left out of the finished film.

16. The ending went through several major revisions.

An earlier version concluded with Nikki dying alongside the rest of her friends.

Barker initially favored a tragic Romeo and Juliet-style finale, but after encouragement from his father and several alternate takes, the creative team settled on the version where Nikki survives.

Navarrette said the final ending emerged almost spontaneously, with the cast and crew immediately recognizing its emotional impact after a single take.

17. Barker already has plans for expanding the story.

Although he’s excited about future projects, Barker has hinted that Obsession could eventually return, either as a sequel or an anthology series centered on the One Wish Willow.

His vision includes standalone episodes following different wishes that spiral completely out of control, potentially directed by a variety of filmmakers while he oversees the overall concept.

Obsession is now playing in theaters.