When an airplane disappears over the Atlantic, Howard Lawson of the TSIB chooses Kendra Malley to lead the investigation, even though she's still on bereavement leave; as a potential crash site is identified, Kendra discovers the pilot kept a secret.

The team pursues leads as they wait to see if the surviving witness will regain consciousness; Theo examines the possibility of mechanical failure; marine expert Nadia pinpoints 716's final resting place on the ocean floor and calls the Royal Navy.

Kendra gets an important clue from Madelyn; a friend of Captain Donovan's appears at the TSIB offices and reveals he was agitated and unstable the night before Flight 716 took off; AJ obsesses over an online conspiracy that blames a Russian oligarch.

Though the flight simulator all but confirms the cause of the crash, Kendra isn't convinced -- especially once Madelyn starts remembering her escape from the plane; Dom suspects that Derek's death was the result of a botched murder attempt.

AJ is injured but alive after his accident; after being attacked, Kendra uncovers a stunning betrayal by someone close to her; a second attempt at reaching the black boxes reveals a new layer to the mystery.

After recovering the black boxes, Kendra investigates Hoffman and brings the full story of the Flight 716 disaster to light.