When British Global Air Flight 716 disappears over the Atlantic, the Transport Safety and Investigations Bureau is called in to spearhead the search for the missing aircraft. Head of the TSIB, Howard Lawson, chooses his most talented protégé, Kendra Malley, to lead the team. Still on bereavement leave after the death of her husband a year earlier, Kendra isn’t sure she’s ready to come back to work, especially with her rebellious teenage stepson AJ about to come home after some time abroad. As rescue ships converge on a possible crash site, Kendra discovers that Flight 716’s pilot, Richard Donovan, was harboring a secret.

The team pursues various leads while they wait to see if Madelyn Strong, the surviving witness of Flight 716, will regain consciousness. Theo examines the possibility of mechanical failure – the plane was part of a new fleet of aircraft, perhaps a critical weakness was missed in the rush to launch? While her colleagues investigate different theories of the case, marine expert Nadia pinpoints 716’s final resting place on the ocean floor, calling in the Royal Navy to recover the black boxes in a daring and time-sensitive mission.

Kendra interviews Madelyn who gives her an important clue. As the team gets to work identifying this new lead, a friend of Captain Donovan appears at the TSIB offices. He tells them he saw Donovan the night before Flight 716 took off, and that he was agitated and unstable. With Donovan emerging as the prime suspect, Janet arranges a search warrant for the pilot’s homes. Meanwhile AJ is nursing his own obsession with the case, as he becomes fixated on an internet conspiracy that lays the blame for the crash on a shady Russian oligarch.

Donovan’s flight simulator all but confirms pilot suicide as the cause of the 716 disaster. But Kendra still has questions, especially once Madelyn begins to recover memories of the passenger who helped her escape the plane. What’s more, Dom begins to suspect that Derek’s death was the result of a botched attempt on Madelyn’s life, suggesting she knows something worth killing for. Meanwhile, AJ hooks up with an anarchist collective planning a protest against Bartok. Kendra’s determined to recover the truth from the plane’s black boxes, even if it means going to Bartok for help.

Kendra races to the hospital to find AJ injured but alive after his accident. He begs her to get his computer; there’s something on it she needs to see. As Kendra searches for evidence, she comes under attack, eventually uncovering a stunning betrayal by someone close to her. As the team considers the implications of a BGA whistleblower’s presence on the doomed flight, Nadia uses Bartok’s submersible to take a second run at reaching the black boxes. But when the spotlights of the sub sweep across the fuselage, they reveal a new layer to the mystery of Flight 716.

With the recovered black boxes en route to the TSIB, Kendra has the team go over everything they have on Hoffman; his information on BGA could be key to bringing down Moreau. Nadia finds Hoffman’s gamer console but Kendra is ambushed before she gets the chance to examine it – someone’s determined to keep what’s on the hard drive secret. But Kendra refuses to back down, luring the conspirators into confronting the evidence and finally bringing the full story of the Flight 716 disaster to light.