When bodies of missing persons start turning up as if ripped apart by wild animals, the Fifth Operational Corps is called in to investigate. Sergeant Major Samson Ware and Captain Bill Bishop head to Newcastle and form an alliance with young photographer Gary Merrin in an effort to uncover the truth. Meanwhile, Brigadier Lethbridge-Stewart and Anne Travers try to find the recently-returned Professor Ted Travers, who himself seems to have disappeared. Their investigations lead them to a World War II veteran, who is a shadow of his former self. How are the disappearances linked to an experiment from the past? And just what is the connection with the missing Professor Travers?