Cain His Brother (William Monk Mystery, Book 6)

Genvieve Stonefield's husband Angus is missing when she seeks William Monk's help to find him. She is convinced that he has been murdered by his twin brother Caleb, a shadowy figure who lives in the slums bordering the Thames and has always hated his respectable businessman brother. Although worried about Hester Latterly's health as she nurses victims of a typhoid outbreak in Limehouse, and threatened by a personal scandal, Monk is determined to bring one of the most bizarre cases he has ever encountered to its conclusion.