An engineer, Victor Hatherley, attends Dr. Watson's surgery after his thumb is chopped
off, and recounts his tale to Watson and
Holmes. Hatherley had been hired to repair a
machine he was told compressed earth into
bricks. Hatherley was told to keep the job
confidential and was transported to the job
in a carriage with frosted glass, to keep the
location secret. He was shown the press, but
on closer inspection discovered a "crust of
metallic deposit" on the press, and he
suspected it was not being used for
compressing earth. He confronted his
employer, who attacked him, and during his
escape, his thumb is chopped off. Holmes
deduces that the press is being used to
produce counterfeit coins, and works out its
location. However, when they arrive, the
house is on fire, and the criminals have
escaped.
When ? How ? Where ? What ? Who ?