R. Austin Freeman 
Mystery Of 31 "New Inn" 

When a Doctor is called to the bedside of a mysterious sick man by the name of Graves, a strange and sinister plot involving poisoning is uncovered. But who is this Graves; a man well travelled who seems to have such a fear of doctors? And who is the villainous Mr Weiss into whose care Graves has been assigned? Doctor Thorndyke is summoned to help solve the mystery of the thirty-first new inn.