This beautiful model to cut out and glue together is the result of arranging five interpenetrating cubes in a highly symmetrical way Each cube is printed in its own colour and so it is easy to see that exactly two cubes meet at every vertex and that there are twelve surfaces defining each face of each cube. There is a strong internal frame and multiple divisions in the golden ratio to discover. Simple and logical instructions followed carefully yield extraordinary results.

This beautiful model to cut out and glue together has twelve sharp spikes emerging from pentagonal cups and forming ten pairs of parallel planes, each in a different colour. None of these ten colours occurs more than once on any spike or cup. When completed, the polyhedron rests on a horizontal surface on just three spikes. Simple and logical instructions followed carefully yield extraordinary results.

Make this collection of seven ingenious paper gadgets which introduce and explain many of the concepts used in cipher machines. Decode the secret messages and then start to understand how cryptographers try to protect information from prying eyes. See also how cryptoanalysts set about breaking such codes and ciphers. A substantial minibook explains the principles of codebreaking, and includes the story of the Enigma machine and Bletchley Park.