The Spiral chapter in Maquette takes a strong tonal shift, throwing players into an abstract world of floating pillars, odd architecture and grey tones. There is also a secret trophy to be earned here called Into the Darkness. It will involve a leap of faith, or more accurately, a step.
The path is pretty linear for much of the level, especially leading up to getting the trophy. Make your way along the path in the cave until you come to the outdoor section. Follow the only available path until you find a lever.
Pulling the lever will cause a new pathway to form, and you can follow this to yet another lever. Pulling this will cause a pathway to form directly ahead of you that is broken in the middle, and another one to form to the right. Follow it to a small building that contains a miniature version of the level.
There is a small piece of path that you can place in the broken section to give you access to yet another small building that is close to the central part of the world.
Walk up there, all the way to the edge, and then step off. You will fall, then respawn where you stepped off and the Into the Darkness trophy will be yours.