There were always those who did not conform: Krist’s wide canvas is peopled with intriguing minor figures like Ah Toy, a Chinese immigrant sex worker; a French frog-catcher, Jeanne Bonnet, who fell afoul of restrictions on cross-dressing; and Mary Ellen Pleasant, a civil rights pioneer who fought to desegregate the city’s streetcars. But these individuals rarely had the means to bend the city to their own tastes and notions of justice.

And when one of the men in power — a married lawyer named Alexander Parker Crittenden — was brazenly killed by his lover, the younger, licentious, murderous woman became the scapegoat, bearing all the sins of the city.

Except for brief vignettes from the trial, Krist’s narrative does not return to the scene of the crime for more than 200 pages. This structure demands a fair amount of investment in people whose motives and morals are muddled, at best. Crittenden, his wife and his lover, Laura Fair, had all migrated to San Francisco from the antebellum South, and carried with them the prejudices of those origins: They were pro-slavery, anti-Lincoln and, in due course, Confederate sympathizers (a cause for which the Crittendens’ eldest son died). “Unfortunately,” as Krist puts it rather mildly, it was Crittenden who, while briefly serving in the California State Legislature, was responsible for writing a “notorious statute” banning the testimony of nonwhite defendants from admissibility in court.

These were people who benefited from the restrictive moral code of a “mature” Victorian city, even as they chafed at its constraints. Crittenden, who is described repeatedly as “restless” or “reckless,” did not amass a great deal of actual influence: His political ambitions were thwarted, and what money he earned ran through his hands like fool’s gold. Still, he moved around the country freely, enjoying, as his frustrated lover put it, “the man’s thousand privileges,” which included leaving his wife and children for months or years on end.

During one of those extended wanderings, in pursuit of the riches flowing out of Nevada’s silver mines, Crittenden met Fair, then a 26-year-old with a young daughter, running a boardinghouse with her mother. “Thrice married — twice divorced and once (somewhat suspiciously) widowed — the hotheaded and independent Fair refused to be fixed by the feminine clichés of her time. Amid the rampant speculation in precious metals, she amassed a substantial investment portfolio and occasionally lent her lover money.