The Quincunx by Charles Palliser
“The Quincunx (The Inheritance of John Huffam) is the epic first novel of Charles Palliser. It takes the form of a Dickensian mystery set in early 19th century England, but Palliser has added the modern attributes of an ambiguous plot and unreliable narrators. Many of the puzzles that are apparently solved in the story have an alternative solution in the subtext.” — Wikipedia