Andy's personal life turns upside-down when she answers a domestic disturbance call and the social worker on the scene turns out to be her long estranged mother, Claire, who abandoned her and her father 15 years ago. Now Andy must deal with her private issues as she works alongside her mother to investigate the secrets of a family in turmoil. Meanwhile, Sam, Nick, Chris and Gail are in a race to find the desperate mother and her two children before she makes a tragic mistake. And Detective Jerry Barber's badge may be on the line when a stash of guns he recovered ends up resurfacing on the streets.