Dmitri

Dmitri was an agent of a foreign power who went undercover as the maitre d' of a restaurant. He carried out a scheme to murder the country's amateur detectives with the aid of their servants, including Mrs H, who had come to resent them for their annoying habits. When the man investigating the murders learned from Iris Wildthyme and Tom that the waitress at Hercule Smith's murder was also the maid at Miss Jane's murder, he went to the restaurant, fought Dmitri, knocked him out and had him arrested. (PROSE: The Sleuth Slayers)