The archway was just wide enough for the car. Still seeing no signs of life, we drove through it. Then we found that it had not been necessary to go through the arch at all. Above us was only half a dome. Beyond the gate we could see where it had been smashed and broken. Overhead, the cover ended with a jagged edge, as if some giant hammer had struck it with a terrific, shattering blow. Before whatever disaster had struck the city, it had been a thriving community, at least a square mile in area. There were ruins of buildings, columns, monuments and narrow streets. The buildings were not like those on earth; they had ramps for entering and leaving the upper floors. The structures had no spires or architectural flourishes, but were strictly utilitarian--plain walls, narrow windows, and doors. Whatever had been used for glass was gone now, probably shattered when the city met its fate. "Wonder how they raised that dome," said Gail. "It might have been blown, like a bottle," I said. We crossed the city and resumed our southward trip. Looking back at the dome, I noted that it was constructed of a shiny, glasslike substance which probably had been transparent at one time. But now it was coated with a fine layer of reddish dust. Centuries had passed since Martians lived here. At the edge of the city stood a monument--a headless camel, a Martian, with his eight arms raised proudly above his spine. "Glory wasn't unknown to the Martians, either," I said. "A trait that springs from the urge to self-preservation," said Gail. "An individual, seeing a glorified image of himself, feels more secure." We left the city after taking photographs. A minute or two later our Geiger counter began buzzing wildly. I slammed on the brakes just as we approached a terrific crater. And now I knew why the city was no longer lived in, why there was no water in the canal, and why the road wasn't used. "The bomb!" I said, almost in a whisper. Mars had its own nuclear war! How long ago, I didn't know. Had I the time I might have measured the amount of radiation and determined approximately when the explosion had occurred. The radiation was not dangerously strong now and I knew the blast had taken place many, many years ago. "You know," said Gail quietly, "maybe this is why the Martians were afraid of us." "They knew we had the bomb and might use it on Mars?" I asked. She nodded her head soberly. "I think the Martians must know a great deal about the earth. More than we ever knew about Mars." "The question is," I told her, "whether they still have the bomb and if they're likely to use it on us." "Maybe they've outlawed it," she said. "If so, they're more civilized than we are." "Maybe the Martians have had more time in which to become civilized," she replied. "Civilization has a way of turning back," I said. "If they had the bomb once, they can build it again."