Humanity has been visited by the Jackaroo, an alien race, who give access to a network of wormholes around which abandoned spaceships orbit. These spaceships, built for long extinct alen races, can be taken over by using 'code', a cross between software and intelligence.But the wormholes lead to a dead end, the motives of the Jackaroo are suspect, and using 'code' can be lethal. The plot involves the theft of suspect 'code' and the police trying to recover it. The story is somewhat overshadowed by the setting and its length makes it feel like an abandoned novel. ( )