The Saint in London

Simon Templar, known as "the Saint," meets and hires Dugan, a reformed pickpocket and ex-convict. Templar's reputation as an adventurer and investigator is established early in the story.

Sir Richard Blake from British Intelligence approaches Templar to investigate Bruno Lang, suspected of espionage activities. Templar agrees to take on the mission.

Templar follows Bruno Lang to his home after meeting Penny Parker, a young woman intrigued by Templar's exploits. He begins gathering evidence against Lang.

Templar steals evidence from Lang's safe, with Penny helping him escape. The theft marks a pivotal moment in uncovering Lang’s espionage activities.

While fleeing back to London, Templar and Penny rescue Count Duni, a French diplomat who was abducted and tortured by Lang’s henchmen. Templar takes Duni to a safe inn.

Duni reveals he was overseeing the printing of new currency, but Lang forced him to authorize the printing of over a million pounds for his own use, establishing the financial motive behind the criminal activities.

Templar’s actions attract the attention of Inspector Teal from Scotland Yard. Templar’s pursuits put him under closer scrutiny as Teal begins to suspect him.

Kussella captures Penny and tells Templar to come alone for her release. Templar rescues Penny and Dugan, only to find Duni murdered and himself framed for the killing.

Templar discovers Duni had contacted Stengler at an embassy shortly before his murder. Templar, Penny, and Dugan raid Lang's house seeking clues about the conspiracy.

In a confrontation, Templar disarms Lang and rescues Penny and Dugan. Kussella is accidentally shot and killed during the chaos, raising the stakes of the investigation.

Back at Scotland Yard, Templar, Penny, and Dugan wait with Blake as Lang and Stengler are arrested for espionage and murder. Templar is cleared by Teal and prepares to leave.

Templar says goodbye to Penny, choosing to leave without forming romantic attachments, concluding his investigation and escape.