Deputy US Marshal Casey Quinn has worked at the St. Louis marshals' office for two years and is given a routine assignment to help transport a reporter to D.C. to testify before a grand jury. Valerie, the reporter, was writing a story about an up-and-coming environmentalist who suddenly disappeared and, she later discovered, whose backers purportedly have ties to a terrorist.  

Mercy Brennan followed in her father's footsteps in a law enforcement career, but she has no interest in any other connection to him. A US Marshal in St. Louis, Missouri, she's assigned to a joint task force with the St. Louis PD that puts her back into contact with her father and in the sights of St. Louis's most powerful gang. When the gang has reason to believe Mercy has possession of some highly sensitive and incriminating information, her boss assigns Mark St. Laurent - a Deputy US Marshal and Mercy's ex-boyfriend - to get her out of town.

Kaely Quinn's talents as an FBI behavior analyst are impossible to ignore, no matter how unorthodox her methods. But when a reporter outs her as the daughter of an infamous serial killer, she's demoted to field agent and transferred to St. Louis. When the same reporter who ruined her career claims to have received an anonymous poem predicting a string of murders, ending with Kaely's, the reporter's ulterior motives bring his claim into question. But when a body is found that fits the poem's predictions, the threat is undeniable.

She faces dangerous situations all the time.... Olympic downhill skier, Harper Young, knows what it’s like to look danger in the face. After all, she does it every time she races down a ski slope. She’s fine with that danger and even excels under the pressure, winning Olympic gold. And as a governor’s daughter, she’s familiar with receiving threats from the general public. But when a stalker turns his sights on Harper, she possesses zero skills to protect herself.

When FBI profiler Kaely Quinn's mother is diagnosed with cancer, Kaely takes time off work to go to Dark Water, Nebraska, to help her brother care for their mother. Upon her arrival, she learns of a series of fires in the small town, attributed by the fire chief to misuse of space heaters in the frigid winter. But Kaely is skeptical, and a search for a pattern in the locations of the fires bolsters her suspicions. After yet another blaze devastates a local family, Kaely is certain a serial arsonist is on the loose.