It: Welcome To Derry Episode 4 Finally Explains Why Pennywise Doesn't Leave Derry

This post contains spoilers for "It: Welcome to Derry."

Pennywise (Bill Skarsgård) has yet to show up in the flesh in "It: Welcome to Derry." But we've already met a dozen (frightening) iterations of It by episode 4 of the show, which reveals the cosmic entity's chilling origin story and how it impacted the Shokopiwah tribe in Derry. This connection was established way back in "It: Chapter Two," where Mike (Isaiah Mustafa) helps Bill (James McAvoy) see the Shokopiwah's ritualistic visions that depict Pennywise's book-accurate origins. To combat the entity, the Losers Club decides to partake in The Ritual of Chüd, which allows the gang to face off against Pennywise and defeat it once and for all.

Episode 4 finally gives us a detailed picture of Pennywise's origins, courtesy of Taniel (Joshua Odjick), whose mind is probed into by the Shining-wielding Dick Hallorann (Chris Chalk). Taniel recounts a local legend about a monster who crash-landed in Derry more than a millennium ago, and how his Native American ancestors were able to evade its attacks for years. The Shokopiwah also notice that the monster was encased inside a shooting star when it fell, and that these glistening star fragments are the only thing it seems to be afraid of. This guarded equilibrium was shattered once the settlers arrived, as they didn't heed the Shokopiwah's warnings and ventured into the monster's hunting territory. As a result, Derry descended into nightmarish chaos. 

While the series stays faithful to Pennywise's meteoric origins from Stephen King's eponymous novel, the presence of the Shokopiwah adds a dynamic layer to this origin story. We also learn that the Shokopiwah underwent great toils to keep the monster trapped decades ago, which explains why It has never been able to leave Derry. Let's dive deeper into it.

Derry is Pennywise's home in a certain sense of the term, as it is his active hunting ground after the crash. He goes through cycles of rampage and hibernation, feeding on the fear and chaos of the town's inhabitants. This vicious cycle prevents Derry from escaping its own darkness, as Pennywise feeds on the town like a parasitic leech. This begs the question: why hasn't this entity moved on to other areas with bigger populations? After all, it would make sense to hunt in places with an endless "food" supply, as blending in with crowds would be child's play.

"Welcome to Derry" sets up the reason in episode 3, which begins with a 1908 flashback featuring a young Francis, who strikes a tender friendship with Rose. After Francis is chased by a shapeshifting monster inside the woods, Rose charges in and drags him out into the clearing, explaining that the monster can't physically leave the area. Francis (James Remar) grows to become the military general overseeing Operation Precept, while Rose (Kimberly Guerrero) runs the Derry antique store. The forest encounter hints at the fact that the monster is confined to a specific area, preventing Pennywise from escaping this prison.

Taniel confirms that the Shokopiwah trapped the monster by creating a perimeter made out of the black star fragments, and the creature has physically remained inside the area. The forest doesn't exist anymore, but a familiar building stands in the area instead: the House on Neibolt Street, where the Losers Club found Pennywise in the first film. With Hallorann and co. seeking to unearth these fragments, Derry seems to be in grave danger. Nothing good can come out of this, as eldritch entities cannot be tamed.