In a family of cops, there's rarely a day when a Capello isn't facing down some form of threat. Still, despite their unpredictable schedules, they always find time for their annual family summer picnic. But this year, a sudden phone call changes everything.

A heavily armed gunman has taken hostages at City Hall. As the force's top hostage negotiator, Gemma races downtown to join the rest of the Hostage Negotiation Team as they scramble to identify the captives--fearing the mayor may be among them. But as they search for answers and struggle to gain control of the circumstances, it becomes clear that the mayor is at the center of it all, just not in the way they initially believed. With time running out, Gemma risks it all--her career and her life--in a last-ditch effort to save the hostages. Now, she needs to figure out how to save herself...