Ice puzzles

"Little Kay was quite blue, nay almost black with cold, but he did not observe it, for the Snow Queen had kissed away the shrinking feeling he used to experience, and his heart was like a lump of ice.  He was busied among the sharp icy fragments, laying and joining them together in every possible way, just as people do with what are called Chinese puzzles.  Kay could form the most curious and complete figures -- this was the ice-puzzle of reason -- and in his eyes these figures were of the utmost importance.  He often formed whole words, but there was one word he could never succeed in forming -  it was Eternity.  The Snow Queen had said to him, 'When thou canst put that figure together, thou shalt become thine own master and I will give thee the whole world, and a new pair of skates besides.'
But he could never do it."

The Snow Queen  Hans Christian Andersen