Capt. Hugh 'Bulldog' Drummond Tom Conway is drawn into a mystery when Dr. Ashley Stedman John Goldsworthy is murdered in his study and two toy soldiers vanish from his desk. The next day, Drummond reads about the crime in the newspaper and is approached by his friend Phillip Coleman [William Stelling], who explains that he owns two similar figures and has already received offers—and threats—to sell them. Coleman leaves the two painted lead figures with Drummond for safekeeping and asks him to look into the affair. To flush out the thief, the pair fabricates a press story claiming that Drummond has bought the figures from Coleman, a gambit designed to draw out the culprits.
A woman who introduces herself as journalist Estelle Gorday [Maria Palmer] joins the intrigue and recognizes the figures from Drummond’s collection on his mantle. Drummond and his ally Algernon 'Algy' Longworth [John Newland] then visit Stedman Manor and meet Cynthia Stedman [Helen Westcott], the victim’s daughter. She explains that her father’s figures were very like Drummond’s but with subtle differences, and that they were part of a set of 13 soldiers acquired at auction along with an Anglo-Saxon palimpsest. Stedman had been translating that parchment when he was killed, and the scroll was stolen. He had been negotiating to sell the set to a man named Edward Vane [Harry Cording], who offered far more money but left angrily when his bid was refused.
Drummond and Longworth accept an invitation from Gorday and attend, but danger quickly escalates as Vane breaks into Drummond’s apartment and makes off with the two soldiers. Coleman and Seymour [Terry Kilburn] shadow him to a Soho flat, where Seymour returns to fetch Drummond and they head back. Upstairs, a knife is thrown at them, and they discover Vane dead and the soldiers missing. The next day, Drummond and his friends find themselves at Inspector McIver’s office. Cynthia identifies the dead man as Vane, confirming the link to the case. Drummond then visits Gorday and notices her perfume, a clue that leads him to the palimpsest. Gorday confesses to working for Vane, who was a collector with a larger stake in the hidden trove.
With the palimpsest in hand, Drummond and Coleman present the parchment to Cynthia Stedman in front of Estelle Gorday and reveal the key discovery: the soldiers encode a history of the thirteen last Anglo-Saxon leaders before the Norman conquest. The parchment also hides a map instructing where Harold’s treasure—found near a manor west of London—might lie. After Hastings, the monks rewrote the original text, and the 13 figures became the cipher to locate the prize. The trio travels to the indicated spot, where a former London manor now houses an antique store. Inside, they uncover a medieval fireplace and hidden walls; when they inquire about the soldiers, the shopkeeper’s clerk directs them to leave.
Gorday visits Drummond again, this time armed and determined to seize the palimpsest. She reveals herself to be Estelle Gorday, daughter of the storekeeper Mr. Prager [William Edmunds], who owns the other nine soldiers and seeks the four remaining pieces and the palimpsest. Prager and his daughter had hired Vane to find them, but the situation spiraled when he killed Stedman. Gorday reluctantly admits to being present at Soho and to throwing the knife at Drummond.
The stakes heighten when Stedman’s daughter and the others wait outside the antique store as Gorday/Prager and Drummond enter. Inside, they discover Prager dead. Coleman, now in possession of all 13 soldiers, confronts Drummond, but a struggle ends with police intervention. McIver arrives and takes a single figure, triggering a mechanism that seals the hidden chamber. Coleman tries to flee but is shot, and crushed as the secret door begins to close. The surviving trio—Drummond, Cynthia, and Coleman’s former accomplices, who had backed away—manage to escape as the discovery is secured and the treasure is revealed, solidifying the thrilling resolution of a case that intertwined history, art, and peril.
