Off the Florida coast, Grace MacBride, partner in software company Monkeewrench, thwarts an assassination attempt on a retired FBI agent. A few hours afterward in Minneapolis, a young girl’s throat is slashed. Later that day, two men are killed execution style. Minneapolis Homicide detectives Leo Magozzi and Gino Rolseth struggle to link the three crimes, but the wave of murders across the country has only just begun. Piece by piece, evidence accumulates, pointing to a suspect—and a motive—that shocks them to the core. It puts the entire Midwest on high alert…and Monkeewrench in the line of fire.