The Three Impostors - Arthur Machen

The Three Impostors; or, The Transmutations is an episodic horror novel by British writer Arthur Machen, first published in 1895 in The Bodley Head's Keynote Series. It was revived in paperback by Ballantine Books as the forty-eighth volume of the Ballantine Adult Fantasy series in June 1972.

The novel comprises several weird tales and culminates in a final denouement of deadly horror, connected with a secret society devoted to debauched pagan rites. The three impostors of the title are members of this society who weave a web of deception in the streets of London-relating the aforementioned weird tales in the process-as they search for a missing Roman coin commemorating an infamous orgy by the Emperor Tiberius and close in on their prey: "the young man with spectacles". (wikipedia.org)