Pirates of the Universe — Terry Bisson

In the shabby, war-torn, depleted Earth of the twenty-first century, Gunther Glenn wants to live in the utopian theme park "Pirates of the Universe." He only needs one more mission as a Space ranger--hunting the enigmatic Peteys, 1200-kilometer voids in space whose "skins" can be harvested and processed into a substance more valuable than gold--to get his chance. But the arrival of a mysterious package and the disappearance of another Ranger ship into the Petey void sends Gun on a mission through the bureaucratic maze of the mother corporation, the virtual-reality maze of the Dogg, and the Escher-like multidimensional maze of the Tangle for the key to his future.