 After a jet liner crashes just outside of Los Angeles, Quincy is called in to help identify the victims as well as to help find out the cause of the crash. However, he is soon trying to solve two other mysteries as well. One involves trying to positively identify a man who was traveling under an assumed name with a woman he was having an affair with. The other involves three chemical engineers who all suffered from lung cancer, which might have been caused by a project they were working on.