A story contained in four parts.

Mostly known from the title of the boxset of Aliens-series films, "Alien Quadrilogy." An awkward mix of Greek and Latin, seen as incorrect by some linguists (despite the common word "television" being a similar combination of Greek and Latin). The Latin-rooted word "tetralogy" means the same thing and avoids the awkwardness.

When you eat dirt for the first time and leave your family to build a shack in the woods

A made up word meaning a 4 part series. people often mean tetralogy when they say quadrilogy.

A series of four.