Lanyard goes from New Orleans to Hawaii to discover how rubies and opium are being smuggled in from Hong Kong.

Mike suspects that the gun offered for sale by a homeless boy was used in a murder the night before.

Mike searches the waterfront for Helen Calder, a missing heiress who can be identified by an emerald ring.

Discovering that a recently deceased man's greedy children are looking for a fortune that he hid before he died, Mike decides to make sure that the money goes to his beloved housekeeper instead.

In Mexico, the death of an archaeologist sends Lanyard in search of a treasure in Aztec gold coins.

In New Mexico, Lanyard is worried about an old friend who claims to have seen a flying saucer and that it's not just one of his tall tales.

Mike challenges an aircraft designer plagued by accidents to pilot one of his own planes.

Lanyard must recover top-secret microfilm that could sabotage a peace conference if it gets into the wrong hands.