A mild-mannered newspaper proofreader saves his publisher from a disastrous libel suit when he finds a misplaced comma; the grateful publisher rewards Hiram with an around-the-world tour.
On the first leg of their around-the-world tour Hiram and Ainslie make landfall in England prior to traveling to Scotland; on a train the two men become involved with a murder, a stolen gem and a poisonous snake.
During his visit to Scotland, Hiram is convinced to impersonate the King of Rovaki, who looks exactly like the American tourist; Hiram discovers the reason for the identity change after someone attempts to kill him.
After finding a message in the hollow handle of his umbrella, Hiram finds himself chased by foreign spies and the Paris police; Hiram performs in a circus as a trapeze artist and an exotic dancer to throw his pursuers off his trail.
Foreign agents are convinced that Hiram's search for an underwater plant is a cover for espionage. Sebastian Cabot.
Hiram's efforts to study the wildlife on the Rock of Gibraltar are interrupted by Romani, Scotland Yard and the British army.
While visiting Monte Carlo, Hiram uses his surefire system to win a yacht in a roulette game, which leads to the discovery of a plot to flood the United States with counterfeit currency.
Hiram uncovers foreign agents' plan to freeze the Pacific fleet in Pearl Harbor with their diabolical weapon.
Hiram's efforts to record the mating call of the elusive Swiss titmouse are put on hold when he discovers a young king's life is in danger.
Hiram's skill as a painter gets him in trouble when his copies of the old masters are mistaken for the real paintings which have been stolen from the Louvre.
Hiram visits a carnival in Genoa, Italy, to take a picture of a rare type of mouse; unfortunately, his photograph captures a pair of camera-shy revolutionaries that are on the lam from the French authorities. Tor Johnson.
Hiram's plans to spend a quiet Christmas in Vienna are disrupted when King Peter is kidnapped.
Hiram learns that spies have kidnapped a scientist's daughter to wrest atomic secrets from the old man.
Holliday is in Sturmzig, a strategically important nation in which a new king is to be chosen. Holliday thwarts the nefarious schemes of the evil Baron; but is inadvertantly chosen king. After he defeats the Baron and his henchman, he abdicates.
While searching for a new species of moth in the Moroccan desert, Hiram uncovers a plot to assassinate four world
Hiram gets in trouble when he innocently agrees to enter into a phony marriage and carry stolen gems across the U.S. border.
While searching for evidence of one of his ancestors, Hiram is shipwrecked on the African coast; Hiram meets an evil Berber sheik and a lot of men who look remarkably like the globetrotting proofreader.
As part of a plot to earn Hiram's trust, a foreign spy undergoes plastic surgery to look like his friend Joel.
Hiram becomes involved in Scotland Yard's investigation into the theft of engraving plates used to print the British pound notes.
Hiram switches identities with a French scientist in an attempt to keep the secret of the first Earth satellite from foreign agents.
Hiram dons a disguise to rescue a Balkan King from captivity.
A Frenchman impersonates a Hindu ruler to claim his weight in diamonds.