This was another excellent book by Aminatta Forna. I read her Ancestor Stones a while ago and loved that too; I recommend both of these books highly.
The Devil that Danced on the Water is a memoir of Forna's early years when her father was alive, and the efforts she goes to to find out why he was hanged for treason by the government of Sierra Leone. I much preferred the first two-thirds of the book when Forna was writing about her childhood instead of the end where she writes about the trial. For me, it wasn't so important to know all the details. But that isn't necessarily the main focus of the book, so it didn't really bother me. The brief vignette at the very end about the couple she meets in Sierra Leone made it worth reading the entire book (although the entire book was worth reading).
So many of these African countries are forgotten; Forna's books bring them to life.