The narrative unfolds in London, where a crowd gathers for a royal event. The protagonist, alongside a detective named Thorndyke, encounters Inspector Badger, who is tracking a suspicious man. This man, after a brief altercation, collapses and is later pronounced dead due to internal hemorrhage. Among his belongings, a sealed letter addressed to Mr. Adolf Schoenberg is discovered, along with a peculiar brown-paper parcel containing a pork pie. The letter, written in an ancient script, piques Thorndyke's interest. He identifies the writing as a form of primitive Semitic, likely Hebrew, and suggests it may be a cipher. Badger decides to take the letter to the British Museum for expert analysis, while Thorndyke suspects the document may hold deeper secrets. The plot thickens when Mr. Barton, a distressed man, seeks Thorndyke's help regarding his brother, who is suffering from a mysterious ailment. Barton believes his brother is being poisoned and presents a sample of his brother's food for analysis. Thorndyke discovers arsenic in the sample, prompting him and his companion to visit Barton’s brother. As they travel, suspicions about Barton grow. Thorndyke deduces that Barton may have ulterior motives, particularly when he notices the timing of their train and the potential for a trap. Upon arrival, Barton’s behavior becomes increasingly erratic, leading Thorndyke to conclude that they are being lured into a scheme. The narrative culminates in a tense confrontation as Thorndyke and his companion follow Barton back to their chambers, where they suspect a burglary is underway. They alert the police, leading to the capture of Barton and his accomplices, who are revealed to be common criminals rather than anarchists. The deciphered document, initially thought to be a cryptogram, turns out to be a message indicating the location of stolen goods. Thorndyke's keen analytical skills and understanding of the document's true nature lead to the recovery of the loot, while the police are left puzzled by the events. In the end, the story highlights themes of deception, the complexity of human motives, and the triumph of intellect over criminality, as Thorndyke successfully unravels the mystery behind the cipher and the criminal plot.
By R. Austin Freeman · First published 1930 · Genre: Mystery, Detective Fiction, Thriller