the series followed the short stories closely with two notable exceptions: first, the detective parodies, although alluded to on occasion, were for the most part dispensed with. secondly, the story arc of the blue russian letters and the search for the agent known as number 16 were also dispensed with. for this reason three chapters ("the adventure of the sinister stranger", "blindman's bluff" and "the man who was no. 16") were not adapted.