This escape room by Bizon Events (opened April 2015) took place in the real abandoned flour mill 'De Sleutels' in Leiden: players ventured into the dilapidated factory to unravel why it suddenly closed its doors in 1988. The authentic industrial location was the main asset — 'the old factory is a beautiful authentic place' — with varied, sometimes surprising puzzles. Reviews were solid but not outstanding (7.8/10 on escaperoomsnederland.nl from 6 reviews); the recurring complaint was too much reading text and weak integration between theme and puzzles. The indoor room closed around 2020 due to the redevelopment of the Meelfabriek complex, not due to lack of interest; the operator still sells tablet-controlled outdoor escape games (EscapeGame, PilgrimGame, RembrandtGame) for large groups.