“Less Than Zero” writer Bret Easton Ellis is set to make his directorial debut with “Relapse,” an elevated horror film he wrote starring “Stranger Things” breakout Joseph Quinn.

Paris-based SND has boarded the project as producer, alongside Adrian Guerra’s Nostromo (“Penny Dreadful”) and Simon Wallon’s Kiss & Kill (“Bonnie”). SND will handle worldwide sales on “Relapse,” as well as French distribution, and will tease the title at the EFM with a sizzle reel.

Quinn, who will next be seen in “Fantastic Four,” “A Quiet Place: Day One” and the “Gladiator” sequel, stars in ”Relapse” as Matt Cullen, who checks into rehab after witnessing a horrific death during a debauched party. Three months later, he is set to get his life back together, staying at his parent’s mansion in the hills of Los Angeles. But things have changed around Matt and everything seems off balance.

“Fueled by his unstable personality and the invading power of social media, Matt’s paranoia grows, messing up with his rehabilitation program. As he starts using again, a mysterious presence starts growing around Matt, and a monster that has been haunting him since he was a teenager reveals itself. His therapist tries to help, convinced that the monster is actually in Matt’s head,” reads the synopsis.