Chasm is the third and final subchapter of Chapter 1: Forsaken City in Celeste. The subchapter tests your knowledge of platform momentum, specifically with traffic light blocks. The Cassette to unlock Chapter 1's B-Side can be obtained in this subchapter. The only story moment found in this subchapter is at the end when Madeline rests at the campfire and notes that this may have been a bad idea.

