Josh Smith is a teen-aged boy with two ambitions; become a rock star and seduce a girl.  When his rich, eccentric Great Grandfather dies, all the other great grandchildren receive $250,000, but Josh only gets one of the old man's ugly modern sculptures. 

He soon discovers the sculpture is not what it appears to be.  It is a Cargan, a device allowing him to travel to an exotic planet where he realizes at least one of his ambitions.  His travels to that planet lead to adventures on other worlds and relationships which entangle him in interplanetary love triangles.  He discovers a sinister plot to take command of other planets involving another Earthman with a Cargan and must help expose it to galactic law enforcement authorities.