Our hero is a knight who secretly entered the castle of the Knights Templar. It was rumored that somewhere in the secret rooms of the castle, the Holy Grail was hidden. It was not easy to get inside, but the search yielded nothing, and when the spy was about to leave the castle, it turned out that the exits were blocked. To open the door, you need to find the code key. Replace the letters with the numbers on the column near the arch in the dungeon and the hero will be able to leave the building safely, though to no avail. Carefully inspect the available rooms, collect numbers, find clues. Properly using them will solve the problem.