Sherlock Holmes and Dr. Watson are spending a restful day in the country, when they encounter a badly injured man who is carrying an unconscious young woman. They take the pair back to their flat in London, and after Dr. Watson has treated them, the man explains what has happened to them. He is Haterley, a hydraulic engineer with a business of his own. He had been hired by Colonel Stark and an associate, who wanted him to fix a large hydraulic press for them. He was taken to the colonel's country home, where their housekeeper tried frantically to warn him about Stark. After a tumultuous encounter, he and the housekeeper had barely escaped with their lives. From other details, Holmes deduces that Stark was involved in counterfeiting. Holmes, Watson, and Inspector Lestrade then set out to finish the case.