Henry gets pissed because another shoe is stolen, this time an old black one.
Over lunch, they discuss the spy's resemblance to the black-bearded Barrymore, the Baskerville butler.
Holmes decides it's too dangerous for Henry to return to the mansion alone, so Watson will go with him, while Holmes will stay in London.
After lunch, the first brown boot is found by luck. But the old black one stays missing.
That night, Holmes grills the driver of the cab that drove the spy. The cabby remembers the spy said his name was "Sherlock Holmes.