Paul and Steve are tricked into attending a party at a large run-down family home. Temple is asked to solve an unresolved murder that occurred there 5 years earlier. Can he solve an illogical crime and prove Stephen Bissett is innocent?
In Stockholm, old friend Ingmar asks Temple for a favour. Temple soon gets embroiled in murder and a drug-smuggling racket, all related to an expensive yacht carrying expensive cargo, neither of which anyone can find.
Paul and Steve take the night train to Inverness. Paul spots a coffin in the mail room, so when Freddie Prince exits the train, at Preston, he gets D. S. Waterhill to help. Sir Harold Malyon says the body in the coffin has been murdered.
Paul and Steve are on a weekend boating trip when they hear a man, in the water, calling for help. Commodore Fairbright comes to help but they discover the drowning was no accident. Paul believes it's insurance scam and they are in danger.
Paul and Steve are on holiday in Greece. Their car breaks down and find help at a Greek mountain village. Luckily they find Yorkshireman, Joe Hardcastle living there. When he is found dead, Paul thinks the village is hiding a dark secret.
Brechand is shot dead by a KGB double who takes his place. Carlton and Springett want Richard Kelly to murder the old Brechand but make it look like a robbery. Instead the KGB man offers to take Kelly, a petty thief in trouble, to Africa.
Paul's friend Dr. Matthew Fox, a well-known Oxford scientist, dies from gas poisoning. Everyone convinced it was suicide, having intentionally tampered with the equipment. Paul believes that Fox's political beliefs may have made enemies.
Paul and Steve take refuge from the winter weather in a Scottish motel. The peculiar behaviour of other arriving guests arouses their curiosity. And who is the mysterious Mr Williams?
The Munich carnival is known all over the world but it also provides ideal cover for some inscrutable criminals. Paul and Steve join the festivities but Paul is there to help Herr Bauman who is getting tormented by mysterious anarchists.
Paul becomes involved in the investigation of a mysterious outbreak in a research laboratory. An intruder broke in but was later found dead in the Cold Room. The only two people that have access to area were Henry Roach and Robert O'Keefe.