What to read after The Man Who Was Thursday (Political Thriller)?

Gabriel Syme is recruited at Scotland Yard to a secret anti-anarchist police corps. Lucian Gregory, an anarchistic poet, lives in the suburb of Saffron Park. They meet at a party and, after a heating debate, Gregory takes Syme to London underground, revealing that he is an influential member of the European anarchist council. The central council consists of seven men, each using the name of a day of the week as a cover. The position of Thursday is about to be elected by Gregory's local chapter and Gregory expects to win the election. However, just before the election, Syme reveals to Gregory after an oath of secrecy that he is a secret policeman. Fearful that Syme may use his speech in evidence of a prosecution, Gregory's weakened words fail to convince the local chapter that he is sufficiently dangerous for the job. Syme then makes a rousing anarchist speech and wins the vote. He is sent immediately as the chapter's delegate to the central council.