When one Coast Guard officer is found dead and another goes missing, Coast Guard Investigative Service special agent Finn Walker faces his most dangerous crime yet. His only clues are what little evidence remains aboard the dead officer's boat, and the direction the clues point to will test Finn and the Guard to their limits. When investigative reporter - and Finn's boss's sister - Gabby Rowley arrives, her unrelenting questions complicate an already volatile situation. Now that she's back, the tug on Finn's heart is strong.

Detective James Holton has been honorably discharged from the Army Criminal Investigation Division due to wounds sustained when an IED blew up near him. Now with the Lake City Police Department, he's rooming with his good buddy and partner, Cole, while he figures out his family dynamics. Physician Assistant Lainie Jackson is eighteen months out from an attempted murder perpetrated by her ex, which ended when she managed to grab the weapon and shoot him. When he appears to have survived and is back to finish the job he started, Lainie insists it's not possible.

Radio-talk-show host Eve Reilly is used to backlash from her pot-stirring on-air commentary and interviews. But now it seems a disgruntled listener is resorting to more than angry words to express their displeasure. When a suspicious package arrives on her doorstep, Eve turns to law enforcement for help. Police Detective Brent Lange can't find any evidence to link the string of unsettling incidents that follows, but he's convinced they're connected. As the harassment grows more menacing, it becomes clear someone wants Eves voice silenced - permanently.

Ann Silver is a cop’s cop. As the Midwest Homicide Investigator, she is called in to help local law enforcement on the worst of cases, looking for answers to murder. Hers is one of the region’s most trusted investigative positions. Paul Falcon is the FBI’s top murder cop in the Midwest. If the victim carried a federal badge or had a security clearance, odds are good Paul and his team see the case file or work the murder. Their lives intersect when Ann arrives to pass a case off her desk and onto his.

As a former smokejumper, arson investigator Bri Tucker knows her way around fires. But after a mysterious blaze takes the life of a former colleague, Bri inherits a curious puzzle from him that raises questions about several fiery deaths. Someone, however, doesn’t want her picking up where he left off in search of answers. When she teams up with ATF Special Agent Marc Davis to solve the puzzle, the case heats up—as does the attraction between them.