Mr Paul Somerset paced backward and forwards in his lodgings angry, perplexed, confused. As the owner of a London mansion he had unwittingly acquired as his guest a dynamiter, a man who proposed to overthrow all the governments  of the world, an anarchist, completely insane yet convincingly plausible. and poor Somerset had allowed himself to become the dynamiter's accomplice.. Worse than that he found himself falling in love with Clara, the lovely assistant to Mr Zero his partner in crime.