3-stage puzzle. The riddle looks like a very large cake with letters at the very top.
The cake shows letters after activation signal- players have to sit down on the pillow (stage 1).
Then cake cyclically shows one by one the letters (stage 2).
With help of special hint (decorated plate with engraving) players decode letters to numbers (stage 3).
By entering mentioned numbers into keypad => external mag.lock opens.
Size of cake: 60cm diameter, height: 50cm. Numpad: 10*10*8cm Pillow: 35*35*15cm