The most playful - and arguably most accessible - novel by the master of inventive science fiction.

Humanity is not alone in the cosmos. The aliens have given a precious relic to the people of Earth: star-stone. But the harmony of the galaxy is endangered when they discover that the star-stone has disappeared.

Likeable Fred Cassidy is an eternal undergraduate. All he thinks he knows about the star-stone is that it came to Earth in an interplanetary trade for the Mona Lisa and the British Crown jewels.

When Fred is accused of stealing the cosmic artefact, he is pursued from Australia to Greenwich Village and beyond, by telepathic psychologists, extra-terrestrial hoodlums and galactic police in disguise. Follow him on his adventures as he enters multiple realities, flipping in and out of alien perspectives, through doorways in the sand.