I have to knock off points for the racism. I at first thought it wasn't so bad because even though the story contained some casual racism I assumed Conan Doyle was just representing the reality of his time. I even was going to give some extra points when the crime was explained because Conan Doyle gave the non-white characters the same depth as his white characters and without spoiling too much made the non-white criminals a lot more symphathetic than his white criminals.

But then came the final reveal about voodoo. I should keep in mind that Conan Doyle's only knowledge of voodoo would've come from white probably racist researchers but it's still uncomfortable. It felt like this story was so close to being a slightly progressive story written by a 1900s white British author. It showed non-white characters with the same depth and motivation usually only afforded to white characters. But sadly the racism got in the way.