One of the most striking sequences from the IT: Chapter Two trailer sees James McAvoy‘s Bill Denbrough traveling through a carnival funhouse and coming face to face with Pennywise on his quest to save a little boy from the killer clown’s clutches, and as it turns out, that scene wasn’t even included in the original script. Nor was it plucked out of Stephen King’s novel.

Rather, it was a request from McAvoy himself that led to the scene’s creation.

“We were missing a vital story beat for Bill where he dealt with his guilt that he caused his brother’s death,” McAvoy recalls in a new chat with Entertainment Weekly. “I said to Andy [Muschietti], ‘What can we do?’…and literally in 50 minutes, he invented a whole new sequence. It was never in the script, and it isn’t in the book. It’s brilliant.”

You can check out a brand new shot from that very sequence below, shared by EW today, along with a new 360-degree experience released today that takes you into the film’s funhouse.

Pennywise returns to theaters on September 6.