Bridge Crossing BY DAVE DRYFOOS - https://www.gutenberg.org/cache/epub/51241/pg51241-images.html

 He knew the city was organized for his
individual defense, for it had been that
way since he was born. But who was his enemy?

In 1849, the mist that sometimes rolled through the Golden Gate was known as fog. In 2149, it had become far more frequent, and was known as smog. By 2349, it was fog again.

But tonight there was smoke mixed with the fog. Roddie could smell it. Somewhere in the forested ruins, fire was burning.