Forensic accountant Owen Casserly (Jake Weber) flees his home with his teenage son Connor (Finn Little) when he discovers he has been targeted by a pair of assassins (Nicholas Hoult and Aidan Gillen) who have been hired to stop him giving evidence in a major corruption case. Connor witnesses the murder of his father after their car is run off the road. Entrusted with important written evidence, he escapes into the dense forests of the Montana wilderness pursued by the killers. Seeking help he runs into smokejumper Hannah Faber (Angelina Jolie) who is stationed at a remote fire lookout tower. Hannah suffers from PTSD from a previous forest fire in which she was unable to save three young boys. Hannah attempts to lead Connor through the forest to safety. Meanwhile the assassins set fire to the forest to divert the attention of the authorities and cover their tracks.