A company's stockholders hold their meeting at a lonely mansion. A mad doctor conducting experiments in the mansion starts to strangle them one at a time with a nylon noose. The survivors must figure out a way to stop him.

A private detective tries to find out how and why some convicts have mysteriously disappeared from the prison of Dartmoor.

Professor Wilkens has invented a formula for a new type of fuel and puts it on a microfiche that he sends to his daughter and her bodyguard, but multiple different mysterious groups, including the "Chinese Carnation", would kill to get their hands on it.

Mike Hilton served eight years in prison for being innocent. When he is released from prison early, he wants revenge on the men who were responsible. But the ex-commissioner in charge at the time, Jack Bellamy, has given in to drunkenness. And Mike's lawyer Cunningham continues to make crooked deals. He holds the key to solving the case. When Bellamy picks himself up again, he and Hilton are able to bring Cunningham and the gangster Whity to justice.

After a truck carrying a cargo of narcotics is held up by rival smugglers, the driver sets out to prove his innocence.

One of Tony and Brad's best with the boys on the hunt for a treasure of missing LSD that has been stolen by a criminal organization. Their quest eventually leads the boys to far-off desert oil ruins where much of the film's best action occurs.

In Ceylon, American Babs Lincoln, daughter of US Ambassador Jefferson Lincoln, is kidnapped. At the same time, an employee of the US Embassy in Colombo is murdered. The crimes bring Joe Louis Walker, alias Inspector X, and Tom Rowland onto the scene, who quickly realize that the cases are connected.