G. K. Chesterton 
The Man Who Was Thursday 

Set in London in the early 1900s, this metaphysical thriller follows undercover policeman Gabriel Syme, who, in partnership with a Scotland Yard task force, attempts to take down underground anarchists. Syme encounters Lucian Gregory, a passionate anarchist who eventually takes him to a secret meeting place. Once there, Syme begins to influence the anarchists and is eventually elected to the central council. In his attempts to destroy the council of anarchists from the inside, he starts to uncover more secrets, each more mysterious than the last. Thick with Christian symbolism, this classic G. K. Chesterton novel will have readers on the edge of their seat until the final secrets are revealed