Possible Clues:

• Plane figure with eight sides
• Stop-sign shape
• Just figure that, besides, there are eight here
• Figure 0 on electronic device held by prisoner
• Ate all the sides of it, by the sound of it
• Figure of a man in charge with label attached
• By the sound of it, ate besides this
• Eight-sided room
• Go on, act stupidly - ruin the figure!
• Besides, one is not one over the eight