The modern-day critics are calling this novel a metaphysical thriller, but, back in 1908, when it was published, this definition wasn't even invented yet. G. K. Chesterton did create an overwhelming story, though, and it's equally adventurous, philosophical, fantastic and thrilling. The story takes place in London, in the Edwardian era, and follows Gabriel, a new recruit at the "mystery group" of police, the top-secret anti-anarchist unit.
He meets up with Lucian, a radical leftist and a poet, and they argue over the true meaning and purpose of poetry and poems. The discussion heats up, and Lucian ends up inviting the rookie cop to an underground, off-the-map "anarchist den", claiming that he's not afraid to support what he believes in openly. He's considered to be one of the leaders of the anarchist circles.
The council is made up of 7 ruling members, and they take the names of the days of the week as a representation of their ideology. The long-awaited position of Thursday is on the line right now, and Lucian really hopes to get it. He's got all the chances in the world to be victorious, but, just before the official results arrive, Gabriel tells him that he's working for the cops and is an underground agent. At the same time, Syme uses the confusion to deliver a mighty speech and win the position. After his victory, they send him to the central council.
Soon, to his surprise, he figures out that the rest of the members are also policemen working undercover. So, the biggest question is - why are they fighting each other when they're supposed to work towards a common goal? The Man Who Was Thursday is a great adventure/thriller that heavily influenced all the modern-day bestsellers in the genre - G. K. Chesterton is often called the founder of philosophical thrillers.