On a sailboat ten miles off the Florida coast, Grace MacBride, partner in Monkeewrench Software, thwarts an assassination attempt on retired FBI agent John Smith. A few hours later, in Minneapolis, a fifteen-year-old girl is found in a vacant lot, her throat had been slashed. Later that morning, two young men are found in their home several blocks away, killed execution style. The next morning, three more men are found savagely murdered in the same neighborhood.

As Minneapolis Homicide detectives Leo Magozzi and Gino Rolseth struggle to link the three crimes, they discover that there have been similar murders in other cities around the United States. Piece by piece, evidence accumulates, pointing to a suspect who shocks them to the core, and a motive is uncovered that puts the entire Midwest on high alert and Monkeewrench in the direct line of fire. Before it's all over, Grace and her partners, Annie, Roadrunner and Harley Davidson, find themselves in the middle of a shocking collision of violence on a remote northern Minnesota Indian reservation, fighting for their lives.