Jo Evans, a whip-smart police chief, plunges her family into a deepening mystery when she discovers a young girl the night of an inexplicable plane crash in the quiet northeastern town and decides to protect her. Who is this child? Where did she come from and what does she know? Benny Gallagher, an investigative reporter, intrudes into Jo's inquiry with his own take on the shadowy evidence.

A mysterious illness takes hold of Piper, while Jo and Benny investigate a powerful tech mogul, Richard Kindred. As Piper's health deteriorates, Jo weighs accepting help from an unknown source. Meanwhile, Alex works to decipher a radio frequency code from Piper's plane crash, and Ed has a follow-up oncology appointment.