The story is set 28 miles outside London in Rockingham, as a sign on the railroad station states.
Plot
An absent-minded Professor Downie (Forrester Harvey) makes a call upon Capt. Hugh "Bulldog" Drummond (John Howard) as he is making plans for his much-delayed wedding to fiancée Phyllis Claverling (Heather Angel) in his ancestral home Temple Tower.
The professor informs Drummond that a fortune was buried in one of the walled off storerooms underneath his estate, and that Downie was in possession of a book written in code that would lead them to discover the treasure. Unfortunately for the professor, someone else also wanted the riches and Drummond once again is dragged into the plot as the code book is stolen, Professor Downie is murdered, and Phyllis is kidnapped.
The film uses flashbacks from previous Drummond films and dream sequences extensively, which has led some to criticize it as tiresome. Oddly, despite the phrase "secret police" in the title, there is nothing relating to any secret police in the plot except Col. Neilsen's quip when several of the characters are together. The production values are high as the sets are of high quality, but the script has not received much acclaim.
