Moments after Kim Brady finishes her first half-marathon, shots ring out, and three of her fellow detectives, all African-American, are hit, two fatally. With no one from Brooklyn South available, she commences the investigation, finding a witness who identifies where the shots came from but who also claims to be descended from a Knight Templar. The media immediately speculate that the shooter is a white nationalist, but Kim refuses to jump to conclusions, and the description provided by her witness leaves room for doubt.

The mayor, in a primary fight for re-election with civil unrest mounting, heaps pressure on the NYPD to solve the shooting as soon as possible, but he is faced with a re-emergence of his feelings for Kim and a jurisdictional turf war over the investigation. Kim must find an outside-the-box solution as well as keeping the mayor at a distance. Her task grows herculean when two more cops are shot and killed in Brooklyn and two after that in Queens. Her ability to work with multiple law enforcement agencies is put to the test, but everything's riding on her seeing what others won't.