In a science class scene, the students watch the 1952 civil defense film Duck and Cover . This 9-minute educational film, featuring the animated character Bert the Turtle, was produced by the US Federal Civil Defense Administration and shown to millions of American schoolchildren during the Cold War to instruct them on how to react during a potential nuclear attack .
During a school biology lesson, the teacher describes a parasitic flatworm called Leucochloridium paradoxum, which is commonly known as the green-banded broodsac. The parasite infects land snails, causing their eye stalks to swell into pulsating, colorful broodsacs that attract predatory birds, thus completing the parasite's life cycle. The teacher's dialogue notes how the parasite physically alters the snail and manipulates its behavior.
While the arrival of It via a meteor crash during the pre-settlement era is established in the original novel by Stephen King, the specific visual depiction and thematic execution of a primordial evil emerging from a fractured celestial object parallels the 1927 H.P. Lovecraft short story 'The Colour Out of Space.' Both narratives feature a localized cosmic corruption that infects the surrounding environment following a meteor strike.
The extended flashback sequence depicting the arrival of It (referred to as "The Galloo") on Earth millions of years ago and the subsequent history with the Sqoteawapskot tribe represents the most detailed on-screen depiction of the entity's origin story to date, expanding upon brief glimpses in Stephen King's novel and the 2019 film IT: Chapter Two.
The episode's title, "The Great Swirling Apparatus of Our Planet's Function," is a direct quote from a Derry High School science teacher's lecture about earthworms and parasites, drawing a thematic parallel to Pennywise's method of preying on and manipulating the fears of its victims.
