I just finished listening to this on audiobook and I'm not sure what to think about it. It was well written and the narration by Simon Prebble is masterful. The book is a fictional memoir by Charles Dickens' friend Wilkie Collins and presents a possible mystery to explain the origins of Dickens' unfinished The Mystery of Edwin Drood.
Interesting story but a poor ending. But it might get me to look into some of Collins' books.