Detective Amber Cross is a crisis situation negotiator with the Hartford Police Department, she who will often put her own personal safety on the line if she believes it would be beneficial to the situation. She is going through a contentious divorce with Edward Cross - one of his complaints being that she places work as a priority over family despite they having made the decision early in their marriage that he, still unemployed, would be the stay-at-home dad to allow her to further her career - with their eleven year old son Oliver Cross now caught in the middle. Making their family situation even more complex is that Amber's boss, the Police Chief, is Edward's father, who often sees Amber putting her life at risk through the eyes as Oliver's grandfather who would like Oliver to grow up with his mother in his life. The latest crisis in which Amber is involved is twenty year old Callum McGill having commandeered a school bus taking ten children hostage, they from Oliver's school. Callum has taken refuge in a fortified warehouse with the children, his demand exactly $743,368 ransom paid specifically by American Imperial Insurance by 1500h before he starts killing hostages otherwise. Amber will learn that Callum, who suffers from mental health issues, namely borderline personality disorder which often manifests itself in aggressive behavior, and who works part-time for the bus company where his mother, Julia McGill, also works as the school bus manager and a driver, has asked for this specific amount as the claim denied by the insurance company for Julia's medical bills, she suffering from a rare form of cancer deemed not to be covered by her policy leaving them in financial ruin. She will also discover that Callum is smart and meticulous in his planning, her thoughts on how to proceed on this intelligence placing her at direct odds with Hamilton, the SWAT team leader, putting Chief Cross often in the middle of their dispute. The level of Amber and Hamilton's animosity only seems to have manifested itself of late. By the end of it all, those still standing will find how smart and meticulous Callum was or was not as it relates to this hostage taking and ransom demand.