"It had a shiny black finish, solid caterpillar treads, a whirling blade—and it was fast. It was seemingly a machine—but hardly the servant of man.

"Veg fired his blaster at it. The projected charge should have heated the metal explosively and blown a chunk out of it. But the polished hide only gave off sparks and glowed momentarily. The thing spun about with dismaying mobility and came at him again, the vicious blade leading.

"At that point Veg realized he was in a fight for his life."

So begins the story of OX, the fantastic tale of an alternate world inhabited by savage robot machines...and three trapped scientists. Their names: Cal, Veg, and Aquilon, the most resourceful—and rebellious—of Earth's dimension explorers, and with them came their alien companions, the mantas. Strange flying beings, half-animal, half-fungus, the mantas possessed the keenest senses of any creatures in the universe, a gift which more than once saved the lives of their human friends. And here was the perfect time for the mantas to use their powers to the fullest.

Somehow the trio had to find the aperture back to their own dimension before each fell victim to the death-dealing mechanical creations that roamed this weird land.

One possible way of returning was with Tamme, an intelligent but utterly emotionless superwoman who mysteriously appeared in the baffling alternate world. Veg opted to travel with her back to Earth, but instead found himself on a loop through perilous dimensions: one with a multicolored blizzard, another with thick, edible fog, still a third with giant menacing plant life.

Just as incredible was the entity encountered by Cal and Aquilon back on the alternate Earth. Consisting of a gaseous cloud and sparkling lights, the telepathic creature referred to itself as OX. It explained that it was a traveler through "alternity"—the entire fabric of probability in both directions of time. With OX's help, the remaining explorers could visit any world they had ever imagined—including the dimension from which they came.

But was there a chance for rescuing their lost friend Veg? Could their frail human bodies withstand the strange forces of OX's vast powers? And most important, could this alien be trusted to return them to the safety of their own universe?

As rich in scientific detail as it is in breathtaking excitement, OX is a masterwork of imagination and a tribute to the creative genius of Piers Anthony, whose previous works include the highly acclaimed novels, Orn and Omnivore.