An absent minded Professor Downie (Forrester Harvey) makes a call upon Drummond as he is making plans for his much-delayed wedding to fiancee Phyllis Claverling. 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.