The Red Thumb Mark: The irrefutable mark of a thief, or the most ingenious frame-up ever devised?

When a parcel of priceless diamonds vanishes from a sealed safe, the only clue left behind is a single, damning piece of evidence: a bloody thumb-print.

In Monica Downey's gripping classic, The Red Thumb Mark, young Reuben Hornby faces certain imprisonment when the fingerprint experts at Scotland Yard definitively match the bloody mark to his own. With motive, opportunity, and infallible scientific evidence stacked against him, Reuben's only hope lies in the brilliant, unconventional mind of Dr. John Evelyn Thorndyke.

As a master of medical jurisprudence and forensic science, Dr. Thorndyke, alongside his loyal colleague Dr. Jervis, refuses to take the physical evidence at face value. Armed with microscopes, chemical analysis, and a relentless dedication to the truth, Thorndyke sets out to prove the impossible: that an irrefutable fingerprint might be the most masterful lie ever told.

Will science save an innocent man, or seal his doom? Step into the atmospheric streets of Edwardian London and join the ultimate game of cat and mouse in this pioneering tale of scientific detection!