It's 1922 and Americans are drinking in speakeasies, dancing to jazz, stepping quickly to the tempo of modern times.

In the ancient city of Cahokia - a teeming industrial metropolis, a tinderbox of every race and creed - peace holds. Just about.

But on a snowy night at the end of winter, two roughshod detectives are called to the roof of a skyscraper.

Their investigation will spill the city's secrets and bring it, against a soundtrack of wailing clarinets, either to destruction or rebirth.