 Flight crash investigators Gaynor Crosswell (Sarah Parish) and Phil Epson (Hugh Bonneville) lead by Marcus Hodge (Ian Glen), are investigating the explosion of a civil aircraft over rural England. The explosion not only killed all on board, but also people on the ground. Despite pressure from both the public and the airline, to declare the crash an act of terrorism, the investigators keep their pace to reveal the truth. The investigation is shattered when it comes to light that not only the long missing daughter of Marcus Hodge was onboard, but also that she is suspected to have smuggled a bomb onto the plane.