In his narration, Dr. Watson notes that this is only one of two cases which he personally brought to the attention of Sherlock Holmes. The story, set in 1889, mainly consists of a young London hydraulic engineer, Mr. Victor Hatherley, recounting strange happenings of the night before, first to Dr. Watson who dresses the stump where Mr. Hatherley's thumb has been cut off, and then to Sherlock Holmes himself. Hatherley had been visited in his office by an odd, suspicious man who identified himself as Colonel Lysander Stark. He offered Hatherley a job at a country house to examine a hydraulic press used, as Stark explains, to compress fuller's earth into bricks, but Stark warned Hatherley to hold his tongue about the lucrative job, which will apparently pay 50 guineas (52 Pounds 10 Shillings, or 52.50 Pounds by today's decimalised system). Hatherley felt compelled to take this work, despite his misgivings, as he had had very little work.
