This novella was recommended to me by Jonathan L Howard, author of the excellent Carter and Lovecraft. It's basically a non-racist re-telling of The Horror at Red Hook.
The first half is the backstory of Black Tom (Charles Thomas Tester), a black man in 1920s Harlem who makes ends meet by doing what looks like low-level gangster jobs (acting as courier, etc) except that the trade is in occult objects, and his musings on how he's not going to allow himself to be broken by manual labour and racism like his father was. This is the better half of the book.
The second half is from the point of view of one of the detectives hired by the family of the mysterious white dude who is buying up lots of slum property in Red Hook and this is where it becomes obvious this story is a re-imaging of Lovecraft's most infamously racist tale. Although it is where most of the action lies, is less fulfilling because the character just isn't interesting. However, the final battle and the outcome are very well done.
A quick read, and definitely worth your time.