Episode 1
Sukru runs a trading company to front a drug smuggling operation, using carrier pigeons to carry the drugs.
Episode 2
Some conmen convince financial journalist Brownley that leading financier Untermeyer is dead. His report throws the stock market into confusion, allowing the conmen to clear up on the markets. Brownley is then murdered.
Episode 3
An unexploded bomb from World War II is found by a dam, and only the makers will know how to defuse it.
Episode 4
An ex-con deported to Italy after serving a prison sentence in the U.S.A., has invited a group of protection racketeers to join him in Naples.
Episode 5
The body of a merchant seaman, reported lost overboard in the Mediterranean, is washed up on the south coast of England with a bullet in his head.
Episode 6
Duval investigates the death of an illegal immigrant killed after he disembarked from a freighter at New York.
Episode 7
Episode 8
Duval investigates the theft of a valuable old master from the collection of Sir Isaac Spendler.
Episode 9
Duval investigates the apparently motiveless murder of a N.A.T.O. courier found in a sleeping compartment on the Black Sea Express
Episode 10
Duval investigates the disappearance of a valuable antibiotic somewhere between New York and the World Health Organization in Sweden.
Episode 11
Duval investigates the theft of four uncut matched stones from an Angolan diamond mine.
Episode 12
Duval investigates the theft of a cargo of valuable platinum from a flight from Rangoon to Hong Kong after the airplane is forced down by a passenger.
Episode 13
Duval looks into the slave trading racket, investigating the mysterious disappearance of many thousands of natives from Mombasa during the annual pilgrimages to Mecca.
Episode 14
Duval is on the trail of forger Eddie Keflik, who has blackmailed a clown in a traveling circus into working for him.
Episode 15
Duval investigates the death of a gang member in Paris and uncovers a murder list.
Episode 16
Author Andrew Slater, writing a book about the war, discovers that Onno van Veer, remembered as a hero of the Dutch resistance, was not executed by the S.S. after all. Duval unearths a tale of treachery and murder.
Episode 17
A man extorts a large sum of money from an insurance company. Interpol begin a tireless operation to track the man through countries that don't have Interpol agreements.
Episode 18
Duval investigates a murder. The victim's husband appears to have the perfect alibi: he was leading the Italian Mille Migla motor race at the time of her death.
Episode 19
Duval investigates the theft of a million dollars worth of platinum by three men posing as a U.S. Navy Patrol, who killed the passengers and crew of the S.S. Jensen.
Episode 20
In Montreal for Interpol's annual conference, Duval catches up with a wanted man who escaped his clutches back in 1939.
Episode 21
Gangster Mike Marko amassed a fortune from the rackets, but did not live to spend it. Duval is on the trail of his right-hand man, Pavone.
Episode 22
Ronald Millais is a gigolo, living off women who fall for his easy charm. Duval investigates claims that Millais has kidnapped a millionaire's daughter.
Episode 23
Schroeder was erroneously convicted of the murder of his business partner, Kaltmann. Duval orders that the ex-convict be watched when he hints at committing the crime for which he has already been punished.
Episode 24
Duval goes to Madrid on the trail of a young couple who have robbed a Tel Aviv bank, using the female's threat to commit suicide as a diversionary tactic.
Episode 25
Diamond dealer Jacob Moltz and his accomplice, girl magician Frankie Silver, devise a foolproof plan to rob the biggest diamond house in Amsterdam, and frame safe-cracker Sash Moran.
Episode 26
The value of paintings by Hugo Ballard begins to soar after his death, so why would his widow slash one of his paintings?
Episode 27
A policeman is shot in the back in the opal mining settlement of Cranby's Creek, in the Australian outback, and the townsfolk claim the shooting was carried out by Emil Brock, who is wanted for murder by Interpol.
Episode 28
Insp. Duval is in pursuit of American financier Pearce Clyde, who is wanted for questioning by the U.S. Treasury. When he arrives at Clyde's hotel in the Himalayas, Duval sets off a booby-trap.
Episode 29
Duval is held up in a small canal town when a strange death occurs. The local authorities think the death is a straight forward suicide, but Duval sees evidence of something more sinister.
Episode 30
Duval responds to a tip-off from an American reporter about a possible organized blackmail racket in a Swiss ski resort and goes to Switzerland posing as his Paris banker friend, Count de Regny. When he arrives in Switzerland he realizes that he has been set up as the next victim.
Episode 31
Interpol is called in when the police find the body of a French girl in the boot of an American car. Everything points to Ben Stack as the murderer, but Duval is not convinced.
Episode 32
Lars Lukas, a French swimmer, is shot after completing a cross-Channel swim from France. It appears to be a motiveless murder until Duval hears a tape recording of Lukas's last words, a lead to a smuggling ring.
Episode 33
Duval is on the trail of Thackeray, an international forger who robs safes and substitutes forged bills for the real thing.
Episode 34
The driver and hostess of a coach tours company have a profitable sideline carrying out armed robberies in the towns that they visit. Duval investigates the shooting of a Paris jeweler.
Episode 35
Duval agrees to help his old friend, Bernarde, the owner of a Paris salon, to keep his latest creations under wraps until the big fashion show, but Harry Grayson and Mamie Bryant have other ideas.
Episode 36
Duval flies to Delhi to locate a consignment of live cholera vaccine stolen from a laboratory in Karachi.
Episode 37
Duval is asked to investigate a gun-running racket in North Africa, and suspects archaeologist Professor Velard of involvement.
Episode 38
Duval goes to South America to pick up Dave Carson, who is wanted for murder. He walks into the middle of a revolution, and has to work side-by-side with his quarry.
Episode 39
Duval is called in after an assassination of an American diplomat. Evidence seems to point to a recently released Nazi seeking revenge. What does puzzle Duval is how he constructs the assassinations.
