The Man Who Was Thursday

The novel centers around Gabriel Syme, a poet and undercover detective who infiltrates the Central Anarchist Council by becoming 'Thursday', one of the seven members named after the days of the week.

As the story unfolds, Syme discovers that most council members are also undercover policemen, leading to a surreal chase and a confrontation with the enigmatic leader, Sunday.

The book explores themes of law versus anarchy, social philosophy, and the nature of reality, with Chesterton's characteristic wit and metaphysical insights.