In Chicago, a young man falls to his death from his nineteenth-story hotel room; in New York City, a sick tourist battles the crowds and her failing body to fulfill a shadowy mission; and in southern Alabama, Ryder Creed and his search-and-rescue dog Grace find the body of a young woman who went missing in the Conecuh National Forest—and it appears she filled her pockets with rocks and walked into the river.

Brought in to investigate one suspicious death, FBI profiler Maggie O’Dell soon learns of an ominous connection between not just the first victim, but multiple other strange events around the country. Before long it is clear that she might be on the trail of the most twisted conspiracy the nation has ever known, and at its heart is a megalomaniacal genius willing to place millions of lives in jeopardy in pursuit of a sinister operation.

With no options left and time running out, there is only one way to prevent a widespread disaster. The government must deploy Ryder Creed and his team of dogs to track and identify this deadly contagion, but there’s a risk. Can they do it without Creed, his handlers, and even the dogs getting infected?