The House of Mammon is a new puzzle for readers. John Sairson, an influential businessman, bought a house about five years ago, after Sir George Lugard, the last of his family, was found dead in the library with a gun in his hand. Theories diverged: some suspected that it was a suicide, but others claimed that he was shot. One thing is clear, John Sairson was involved in questionable business. But did he kill his family member?