Despite its reputation as a carnival of vice, Tijuana was, until recently, no more or less violent than neighboring San Diego, its sister city across the border wall. But then something changed. Over the past ten years, Mexico’s third-largest city became one of the world’s most dangerous. Tijuana’s murder rate skyrocketed and produced a staggering number of female victims. Hundreds of women are now found dead in the city each year, or bound and mutilated along the highway that lines the Baja coast.

When Dan Werb began to study these murders in 2013, rather than viewing them in isolation, he discovered that they could only be understood as one symptom among many. Environmental toxins, drug overdoses, HIV transmission: all were killing women at overwhelming rates. As an epidemiologist, trained to track epidemics by mining data, Werb sensed the presence of a deeper contagion targeting Tijuana’s women. Not a virus, but some awful wrong buried in the city’s social order, cutting down its most vulnerable inhabitants from multiple directions.

Werb’s search for the ultimate causes of Tijuana’s femicide casts new light on immigration, human trafficking, addiction, and the true cost of American empire-building. It leads Werb all the way from factory slums to drug dens to the corridors of police corruption, as he follows a thread that ultimately leads to a surprising turn back over the border, looking northward.

The city of Tijuana may not have the cleanest of reputations, thanks to its decades-long media portrayal as a hotbed of gang activity, drug deals, and sex work. Readers familiar with this Tijuana might be surprised to learn that, until relatively recently, Tijuana was no more dangerous or unsavory than its American neighbor, San Diego. So what changed? Who suffered as a result of those changes? And who profited?

A work of incisive journalism, City of Omens holds a microscope up to political maneuverings, sociological phenomena, and public health crises to answer these questions. Dan Werb’s conclusions take him into the gritty world of a struggling city, and the web of closely-related problems—toxins in the drinking water, rampant drug use, violent crime, to name a few—that plague it. Most tragically, he finds that these problems disproportionately affect women. In fact, the deeper Werb digs, the more his epidemiological study begins to feel like a true crime search for thousands of dead, or missing, women.

An investigative whirlwind as well as a gripping narrative of a city reckoning with its sins, City of Omens will engage, surprise, and even haunt readers.