It Welcome to Derry Episode 4 Review: Pennywise Origins and Terrifying Twists

The latest episode of "It: Welcome to Derry" has fans and critics talking about its terrifying revelations and how it deepens Stephen King's horror universe. Episode 4, titled "The Great Swirling Apparatus of Our Planet’s Function," uncovers Pennywise’s horrifying origins and introduces shocking twists that change how we see the sinister creature from Derry. This episode balances creepy visuals, engaging storytelling, and dark lore, making it a must-watch for horror fans.

Pennywise's Origins Revealed: A Journey Into the Past

One of the biggest moments in episode 4 is the detailed look into Pennywise's ancient origins. The episode explores the legend of the Galloo, a primal evil spirit that was trapped in a falling star long ago. The storyline explains how Pennywise came to Earth and settled in Derry, Maine, where it preyed on generations of children. This deep dive into his past provides fans with a new understanding of the creature’s evil roots, enriching the Stephen King universe with historical and supernatural layers.

Terrifying Legends and Stephen King Lore

The series blends Stephen King's storytelling with real Native American legends, suggesting that Pennywise's presence in Derry is part of a much larger cosmic evil. The show depicts Native tribes fighting to contain this primordial monster, a storyline that ties directly into King's novel. 

"It: Welcome to Derry" Episode 4 is a game-changing installment that deepens Pennywise's terrifying origins while delivering chilling twists. With rich storytelling, haunting visuals, and expanded lore, it stands out among horror series and keeps fans eager for more. This episode not only thrills but also provides valuable insight into the darker, cosmic side of Stephen King’s universe.

Shocking Twists and Visual Thrills: Keeps Viewers on the Edge

Episode 4 doesn’t just reveal history; it also delivers intense twists and terrifying visuals. Notably, the episode features a spine-chilling scene where young Marge’s eyes grotesquely mutate, creating a disturbing horror moment that stays with viewers. Critics praise the episode’s inventive visuals and how it pushes the limits of horror storytelling with shocking scenes and compelling character arcs.

Highlights of the Episode:

• The creepy origin story of Pennywise, grounded in Native American legends.
• The appearance of the ancient evil spirit Galloo.
• A nerve-wracking final fifteen minutes that go full-bans in revealing Pennywise’s cosmic background.
• The return of familiar horror elements, combined with fresh, terrifying twists.

Focus on Adult Characters: Expanding Stephen King’s Derry Universe

While previous episodes focused heavily on children, episode 4 shifts gears, honing in on the adult characters and their quest to unravel the mystery of Pennywise. Characters like Leroy Hanlon and Dick Hallorann uncover clues about Pennywise’s cosmic presence, which adds rich depth to the story.

Why This Matters

The episode bridges the gap between the movie adaptations and the original novel, making the horror more complex and layered while also paying homage to Stephen King’s writing style, including his themes of cosmic evil and legacy.

Just watched episode 4 "The Great Swirling Apparatus of Our Planet's Function" of ”It - Welcome to Derry”. Pennywise's past has been revealed. The eye horror was very shocking! #It #ItWelcomeToDerry #WelcometoDerry #StephenKing #HBOMax pic.twitter.com/zTETkACFWF

— AlphaPower65 (@ken2158) November 18, 2025

Critic Reviews and Audience Reactions

Critics are highlighting this episode as one of the series' strongest yet. Many praise its storytelling, visual effects, and suspense, although some note that certain scare scenes could be more effective.

• Fans appreciate the new revelations about Pennywise’s background, comparing it favorably to previous horror series.
• Some viewers say the episode’s most intense moments are right at the end, with the origin story of Pennywise being the real highlight.