In this strange, haunting novel of anarchists and undercover policemen, Gabriel Syme is sent by Scotland Yard to infiltrate the Central Anarchist Council, and soon finds himself voted to the position of 'Thursday'. As Syme digs deeper, his discoveries about the anarchists and their plans lead to a desperate chase across Europe. But he has still to face the greatest terror that the Council has: the leader, Sunday . . . G. K. Chesterton's exploration of cultural pessimism and religious conviction mixes nightmarish paranoia, parable and political humour, and has been described as the best spy book ever written.