British agent Bulldog Drummond is assigned to stop a master criminal who uses beautiful women to do his killings.

Demonstrating that a little knowledge is a dangerous thing, a convicted strangler studies the paranormal and finds a way to render himself invisible. Once he escapes, he sets out to find and eliminate five women who remind him of the mother he murdered. A police lieutenant sets out to safeguard them and bring the invisible killer to justice.

When Count Contini attempts to destroy the world's economy by masterminding the theft of $1 billion in U.S. gold, ICE chief MacDonald summons secret agent Matt Helm to stop him.

The outbreak of World War I places Scots officer Geoffrey Richter-Douglas in an uncomfortable position. Although his allegiance is to Britain, his mother was from an aristocratic Bavarian family, and he spent his summers in Germany as a child. When Geoffrey is approached by a German spy who offers him a chance to defect, he reports the incident to his superiors, but instead of arresting the spy they suggest that he accept her offer--and become an Allied agent. In Germany, among old friends, Geoffrey discovers that loyalty is more complicated than he expected, especially when he finds himself aboard the maiden voyage of a powerful new prototype Zeppelin, headed for Scotland on a secret mission that could decide the outcome of the war.