The pearl, of course, is the cursed Borgia Pearl, an object of rich men's lust. The "he" is Giles Conover (Miles Mander), a master criminal as cruel as he is clever, as contemptuous of men as he is unmoved by women.
The Borgia Pearl has been the object of criminal stratagems since it arrived in London for display in the British Museum. The director of the museum is immensely proud of how he has harnessed electricity to warn of any untoward action involving the museum's objects. But what happens when Sherlock Holmes (Basil Rathbone) apparently makes a mistake. And what happens when the electricity doesn't work.
It will be Sherlock Holmes, aided by his game but confused partner, Watson (Nigel Bruce), against Giles Conover. Holmes makes his disdain for Conover clear. "I don't like the smell of you -- an underground smell, the sick sweetness of decay. You haven't robbed and killed merely for the game like any ordinary halfway decent thug. No, you're in love with cruelty for it's own sake."
Little does Holmes realize that Conover has a creature of his own...a brute whose face is the result of a disorder of the pituitary gland. Watson might call it acromegaly. Most laymen would say it's the Easter Island Statue Syndrome. It's not long before Holmes must deal not only with Conover, but also with this creature...the Hoxton Creeper (Rondo Hatton). "A monster, Watson," Holmes says, "with the chest of a buffalo and the arms of a gorilla. His particular method of murder is back breaking. And it's always the same...the third lumbar vertebrae." "How horrible," says Watson.
Does Sherlock Holmes best the Creeper? Does he recover the Borgia Pearl? Does Conover taste the bitter brew of utter defeat? You'll get no spoilers from me.
Some think macaroni and cheese is the perfect comfort for what ails you. I think it's Rathbone and Bruce. People can argue about which actor has been the best Sherlock Holmes, but there is something about Rathbone's style, earnestness, profile and line delivery that makes me sit back and smile every time I watch him play The Great Detective. All that Victorian gaslight, fog and cobblestones help, too. With some strange alchemy, the Holmes movies with Rathbone have turned into an elixir of kitsch, style, remembrance of things past, satisfaction and noble causes. Mac and cheese doesn't come close.