Why-II?
How come this amazing film with a lot of suspense and only small holes in the plot is not being discussed much more? It is one of the most highly ranked in this 'season' of Sherlock Holmes, and it is a pearl!
It beats hundreds of so-called modern crime stories hand down.
From the first scene with the tired old man on board the ship to Dover,
through the next disappearance of the pearl, the start of the murder sequence, to Holmes finding out the really amazing reason connected to Napoleon, the visit at the ceramics manufacturer and the shop, and the scenes towards the end, when everyone comes out in the open.
[I edited my post when I learned that the Creeper was not a mask, but the genuine disfiguration of a gentle person from poisoning suffered through WW1. I feel sorry for him, to be exploited in this way, actually.]
The movie overall is fully recommended!