IT WAS A QUARTER of an Earth century before Mars was again visited byhumans. Six years after the Envoy was silent, the drone probe Zombie,sponsored jointly by the Geographic Society and La Société AstronautiqueInternationale, bridged the void and took up an orbit for the waiting period,then returned. The photographs taken by the robot vehicle showed a landunattractive by human standards; her recording instruments confirmed thethinness and unsuitability of the Arean atmosphere to human life.

　　But the Zombie’s pictures showed clearly that the .canals“ were engineeringworks of some sort and there were other details which could only beinterpreted as ruins of cities. A manned expedition on a major scale andwithout delay surely would have been mounted had not World War IIIintervened.

　　But the war and the delay resulted eventually in a much stronger, saferexpedition than that of the lost En my. The Federation Ship Champion,manned by an all-male crew of eighteen experienced spacemen and carryingmore than that number of male pioneers, made the crossing under Lyle Drivein only nineteen days. The Champion landed just south of Lacus Soli, asCaptain van Tromp intended to search for the Envoy. The second expeditionreported to Earth by radio daily, but three despatches were of more thanscientific interest. The first was:

　　.Rocket Ship Envoy located. No survivors.“The second worldshaker was: .Mars is inhabited.“The third was: .Correction to despatch 23-105: One survivor of Envoylocated.“