The Adventure of the Engineer’s Thumb is only one of two cases where Dr. Watson brought to the attention of Holmes, so says Watson. A hydraulic engineer, Mr. Hatherley has been employed for a consulting job. His job is to find out what is wrong with a machine supposedly used to compress fuller’s earth into bricks.
From the get go the job was a pretty shady one. Mr. Hatherley being an orphan and living alone was paramount because absolute secrecy was required for this job. Mr. Hatherley was to take the very last train out to the country and would have to stay the night at his employer’s place because it was too late to get passage home. Mr. Hatherley was desperate for money and so took the job willingly.
How does Mr. Hatherley fare, even after being warned by a beautiful girl living in the employer’s house to stay away? Well, you know, RTFO (read to find out).