Peter Ackland is ordered to rest by his Doctor. He travels to Cornwall and is greeted by Henry Braddock at the door of a cottage below the 'skytip'. Braddock has a revolver in his pocket. Ackland also comes across Nathan Murrison and his valet, who divide their time between exploring the 'skytip' and propping up the bar of the Green Dragon; a charming young lady who, on behalf of a Member of Parliament, tries her hand at burglary; other less charming characters who try their hand at blackmail; and a stage that is all set for murder.

A blanket of fog grounds a flight in Brussels and Dr. Andrew Maclaren finds himself sharing a room with a fellow passenger who by morning disappears in suspicious circumstances, leaving behind an envelope hidden under the carpet. Whilst the contents are seemingly innocent, they lead the young Doctor into nightmarish adventures, culminating in the avoidance of cold-blooded killers in a deserted windmill and in the company of a beautiful redhead.

Vincent Flavius, a millionaire industralist, charters a cabin cruiser owned by Ross Barnes. Rumours abound, and most appear to suggest Flavius is on the verge of engineering yet another of his sensational financial coups. Embarkation is set for Cannes, but that is where the trouble begins. Shock after shock follows a strange encounter Barnes has with a girl in a dingy cafe. Murder and kidnapping follow, along with a dangerous chase which brings the Sûreté Nationale into swift action.

When Arthur Abdel Simpson first spots Harper in the Athens airport, he recognizes him as a tourist unfamiliar with the city and in need of a private driver - in other words, the perfect mark for Simpson’s brand of entrepreneurship. But Harper proves to be more the spider than the fly when he catches Simpson searching his wallet for traveler’s checks. Soon Simpson finds himself blackmailed into driving a suspicious car across the Turkish border. When he is caught again, this time by the police, he faces a choice: cooperate with the Turks and spy on his erstwhile colleagues or end up in one of Turkey’s notorious prisons.

An early classic of espionage fiction. Through the cafés, trains and nighttime cities of Europe, Charles Latimer follows a twisting trail of drug-smugglers, thieves and assassins that will lead him to Dimitrios.