This audiobook is narrated by an AI Voice.
When a trusted young clerk is accused of stealing £30,000 worth of diamonds from his uncle's city safe, the entire case rests on a single blood-red thumb-print on a scrap of paper. The police are certain: fingerprints never lie, and the match to the defendant's left thumb is mathematically proven to be one in four thousand trillion. But forensic detective Dr. Thorndyke sees the truth no one else notices: that blood was artificially defibrinated, that a fresh bleeding finger could never make such a perfectly clear print, and that the 'irrefutable' thumb-mark is itself an elaborate forgery—stolen, copied, and planted to frame an innocent man. A groundbreaking early forensic mystery novel that invented the scientific detective genre, packed with courtroom drama, fingerprints, typewriter side-writing, and a clever twist ending.