Into the woods is a structural analysis of writing for screen (television and film) that explains how act structures work and how even experimental writers fall into these structures because they match the natural cadences of satisfying storytelling.
This was a really readable book (perhaps supporting his analysis) and helped me both "read" films and understand how stories fail.
It also intersects with things like the Hero's Journey and the Seven Basic Plots by showing how these structures are actually incorporated into scripts.