The Four Men of the title are British WWI veterans who decide to work secretly against enemies of the country. They aren't above a bit of murder or sabotage to serve their ends, but they consider themselves to be true patriots.

A young woman finds herself as the intended victim of a murder plot on a transatlantic flight from London to New York.

When her husband is wrongly accused of murder, an opera singer sets out to find the real culprit.

After Larry Darrent accidentally kills his lover's blackmailing husband, someone else is arrested for the crime. When he is found guilty, Larry and Wanda have just three weeks together before he must give himself up or let an innocent man go to the gallows.

An American insurance adjuster, stranded in Havana, becomes involved with an archaeologist and a collector of antiquities in a hunt for treasure in the Mexican ruins of Zapoteca.

A man goes on the run from hardened smugglers.

Down-on-his-luck Mike Cormack is hired to fly to a Caribbean island to retrieve a missing ruby. On the island, possibly involved with the ruby's disappearance, is his ex-girlfriend.

Young, idealistic, newly qualified Scottish doctor Andrew Manson arrives in Wales and takes his first job in a mining town, and begins to wonder at the persistent cough many of the miners have. When his attempts to prove its cause are thwarted, he moves to London. His new practice does poorly, but when a friend shows him how to make a lucrative practice from rich hypochondriacs, it will take a great shock to show him what the truth of being a doctor really is.

The aging Julius Caesar finds himself intrigued by the young Egyptian queen Cleopatra.