During the iconic scene in Stephen King’s IT when Pennywise kills Georgie, the monster changes its eyes from yellow to blue, for a very creepy reason. One of the biggest successes in the history of horror, 2017’s IT arrived on the back of a wave of hype, and thankfully managed to live up to it. Reviews from critics were positive, and IT broke the bank at the box office, raking in $700 million, and becoming the highest-grossing R-rated horror film to date.

While IT’s level of success surpassed expectations, there was never really much doubt it would do well. Not only is it an adaptation of one of the most popular authors in the world, it’s an adaptation of arguably the best book Stephen King’s ever written, which is saying something. IT had also famously been turned into a beloved 1990 TV miniseries, starring Tim Curry as Pennywise the Dancing Clown, the eater of worlds, and of children.

Hands down the best known scene from any version of IT comes early in the story, when Pennywise lures in young Georgie Denborough, eventually claiming the boy as his latest meal. It’s a terrifying scene, and one executed to perfection by IT director Andy Muschietti.

IT: Why Pennywise Changes His Eye Color Before Killing Georgie

So anticipated was the 2017 IT film’s take on Georgie’s death, that most of the scene was actually released online before IT’s theatrical debut in an effort to promote the movie. It was a smart move, as the scene quickly made clear that Bill Skarsgard’s version of Pennywise would be the stuff nightmares are made of, and that this adaptation wouldn’t pull any punches in the creepiness department. One aspect of Georgie’s death scene that wasn’t part of the miniseries adaptation was Pennywise changing his eye color during their conversation.

In the 2017 IT movie, Pennywise’s eye color changes from yellow to blue during his exchange with Georgie, and while it goes by quickly in the film, Stephen King’s book reveals an insidious reason behind the color swap. On the page, the scene is told from Georgie’s perspective, and early on he remarks on the creature’s yellow eyes, the color he always imagined a monster waiting for him in the basement would have. A bit later on, Georgie thinks that he must have been mistaken, as Pennywise’s eyes were now a bright, inviting blue, the same color as his mother and brother Bill’s eyes. Being such a powerful being, Pennywise clearly sensed that the yellow coloring was unsettling to Georgie, so he changed his eyes  to blue on the fly as a way to make Georgie associate him with family and safety. This made Georgie all the easier to lure in to his bloody demise.

More: Everything Pennywise Transforms Into In IT Chapter One & Two