Synopsis: From the front flap of the Scribner first American edition: "An unmanned Russian spacecraft, containing soil samples gathered from the surface of Mars, crashes near a remote Bolivian village. The Indians who salvage the remains of the spacecraft fall into a mysterious comatose condition, and only two recover: Julio, young proud, ambitious, and Angelina, his beloved. Reawakening, they are conscious of a strange new awareness of themselves and the world outside. Julio believes himself to be the Inca - the divine imperial ruler - reborn, with the duty of restoring to the Indians their former dignity and glory. At the same time that the Martian soil has so oddly affected the two Bolivians, a manned American spacecraft is on its way to Mars to deploy a device that will render the planet suitable for human habitation. It is essential that the three-man crew be warned of the unexpected danger the planet's soil presents. Inside the ship tension is high after the 240-million-mile voyage, and when at last Mars is reached, the deadly soil adds an extra dimension to an already explosive situation. What constituent of the Martian soil causes its uncanny effects? The answer may be the clue to a vital discovery about human evolutionary potential."