When a man's body is discovered in a crate unloaded from a boat at a Baltimore dock, Craig flies to South America with orders to infiltrate a 'hit' squad, a team of assassins prepared to kill anyone for money.
Assasination attempts on a haughty Arab princess makes her continued stay at a Swiss finishing school impossible, so Craig must risk getting her safely to the airport, and accompany her on the flight home.
In Egypt, Miller insists he's just seen a famous British sportsman in passing at his hotel- the problem is, the chap's been dead and buried for a week. He insists on investigating and uncovers a connection with a smuggling ring.
A scientist refuses to do further work on a British rocket system after he gets a glimpse of his supposedly dead daughter. Craig is sent undercover to a hostile country under cover as toy maker at a trade show to locate her.
Miller is sent to investigate a British mining corporation in a jungle-choked, revolution-infested far eastern country. After attempts on his life, it's determined that the whole operation is only a cover for international arms smugglers.
When a paratrooper's chute fails to open during a training exercise and secret telemetry equipment is stolen from a top secret base and turns up in Germany, agent Tony Miller is assigned to investigate.
In the guise of a publicity agent, Miller must deal with a Russian dance troupe in London for a cultural exchange, but are rife with Soviet spies. He must decide if a dancer's efforts to defect are legitimate.
A shady minor crook is persuaded to assist Miller in uncovering an international drug and arms smuggler's operations in Rome, where a shipment of high-powered rifles are destined for some revolutionaries in southeast Asia.
GS agents Miller and Carter are sent to Scotland to protect a female double-agent who holds the secret of a plan to overthrow a pro-British government. Jean finds herself used to bait to the enemy into the open.
A Swiss agent convinces the squad to investigate an apparently legitimate high class Au Pair agency, who's girls seem to vanish when they start work in England. Sally is sent undercover to infiltrate the agency, and finds drugs, prostitution and murders in the offing.
Craig is drugged in a pub, taken to a mysterious doctor's surgery that he can barely remember later. The Surgery was actually a caravan and the "Doctor" used a truth drug to extract top secret information that he now plans to blackmail the squad with.
Working undercover as butler to a foreign diplomat. GS agent Tony Miller discovers that the man is being blackmailed by an unscrupulous foreigner, who threatened to make known the man's gambling debts.
Sent to the Middle East to trace a lost expedition, Nick Craig meets a beautiful girl who claims she has proof that a group of terrorists intend to blow up a seat of government. The agent attempts to deliver her film of the terrorists' activities to the authorities - but the terrorists are closing in around them.
An underground smuggling network promises people behind the iron curtain a chance to escape to England-at a high price. Trouble is, they're disappearing instead. Miller becomes a pilot to infiltrate the gang.
A top secret gas has been stolen from a government laboratory by a pacifist scientist. He works with an American crook who is trying to sell it to a foreign revolutionary. Craig finds that instead of being a harmless gas that temporarily paralyzes, it's quite lethal.