Trilogiya_trilogy -

: A 1975 horror film featuring three distinct segments, most famous for a story about a woman terrorized by a Zuni fetish doll that comes to life.

A standard trilogy often follows a three-act structure applied across three separate entries:

If you are looking for a specific story involving three parts, here are some notable examples:

(by Deborah Harkness): A fantasy romance following a historian who is a secret witch and her relationship with a vampire while they search for a lost manuscript.