A deadly, incurable disease creeps silent through Chattanooga. And its victims aren’t random.

When inexplicable human rabies cases appear in Tennessee, disease ecologist Letty Duquesne jumps at the chance to trace the virus back to its source. But the closer Letty gets to finding the outbreak’s origin, the further someone will go to stop her.

With an unwanted promotion threatening to take Letty far from the fieldwork she loves, this outbreak feels like her last chance to make a difference. It’s not something she can ignore, especially now. The spillover of zoonotic diseases to the human population is on the rise and violent animal attacks-like the one that killed her sister-are becoming all too common.

Something in nature has gone very wrong.

Local authorities would rather she go home, but Letty can track a source animal like no one else. With the help of disgraced detective Andrew Marsh, Letty follows the virus’s epidemiological trail. But her every move is watched. And the source animal is closer than she thinks.