After two centuries of colonization, the air struggle on Mars was still so critical that the V-L Law, the Vegetative-Lynch Law, was still in effect. It was a killing offense to endanger or destroy any plant vital to the transformation of Mars' carbon dioxide atmosphere into an oxygen atmosphere. Even blades of grass were sacred. There was no need to erect KEEP OFF THE GRASS neons. The man who wandered off a path onto a lawn would be instantly shot. The woman who picked a flower would be killed without mercy. Two centuries of sudden death had inspired a reverence for green growing things that almost amounted to a religion.