“My, my, I need you young people to keep me on my toes,” he chuckled. “Now take a look at these images. These are the beautiful sculptures of Mr Hart. And this is the three- dimensional Sierpinski triangle. Look at this icosahedron, and this … Oh dear, I need my glasses. Such is old age … Now I wonder where they are. I had them a minute ago!” He stepped away to search for them.
While Mr Hedgehog had his back turned, the children crowded round the book, impatient to find some clues. Gelio noticed that the corner of one of the pages was turned down and they eagerly opened the book at that place and found some draft information about a mysterious sculpture. The word 'cryptogram' jumped out at them and they could see some random letters organised in blocks of four squares. They also glimpsed a sculpture with the title printed under it: 'Hidden'.
“That's what we've been looking for,” said Amartia in
her typical flat, economical fashion.
Mr Hedgehog returned waving his glasses, which were heavy horn-rimmed ones with little mathematical symbols on the earpieces. He put them on his nose.
“Ah, I see you found it,” he approved, peering keenly at