History of Unknown Antechamber

Overview

Unknown Antechamber is a hidden chess-puzzle activity from Episode: Heresy, reached via Eris Morn's throne world: from her Flat in the HELM take the green portal, drop off the northwest edge of the platform, and interact with "Pick up the King?" on the chessboard. It is described as "a space where a puzzle may be unraveled, piece by piece."

Mechanics

You move pieces and use plates to add, remove or change pieces within a limited number of actions per puzzle. There are 27 puzzles (Middlegame: "A game is afoot..."); afterwards you can re-enter and choose Endgame ("The real game has begun..."). The puzzle ties to the En Passant triumph and the Uncharted Space destination.