one room a day
Five rooms a week, any three open the vault. Monday to Friday adds a room. The weekend adds none, and is there for the rooms you skipped. Every room in the current week stays open all week.
The answers are not in this page. Each week's key was split into five pieces and thrown away, and each piece was locked with a key made from one room's own answer. Nothing here compares your answer to a stored copy, because there is no stored copy. That is also why the share line cannot be faked.
Nothing leaves your device. No account, no analytics, no calls out. Your progress lives in this browser, and start over clears it.