One defining characteristic of the Sherlock Holmes stories is Sir Arthur Conan Doyle's use of a frame story, or a story within a story. In "The Adventure of the Speckled Band," the main narrative consists of the events of Sherlock's investigation. However, Watson narrates the investigation from a later point in time. By enclosing the main narrative within this framework, Doyle makes the crime feel more realistic and thus heightens the suspenseful tone of the story. Moreover, the frame story structure allows Watson to play a more active role as the narrator.
In particular, the frame story structure allows Watson to include an introductory passage before he begins describing the adventure. In "The Adventure of the Speckled Band," this takes the form of a pronouncement that the adventure that Watson is about to recount is "singular" among all the cases he investigated alongside Sherlock. Watson also goes on to note that the Roylott case is shrouded in rumor and mystery. Through these grandiose statements, Watson heightens the reader's anticipation for the story to follow.
In addition, the frame story allows Watson to insert information throughout his narrative that he could only have acquired after concluding the investigation. For instance, when he describes Dr. Grimesby Roylott's deathbed "shriek," he notes:
They say that way down in the village, and even in the distant parsonage, that cry raised the sleepers from their beds.
This observation emphasizes the horrifying nature of Dr. Roylott's cry. However, it also disrupts the chronology of the narrative. By establishing a frame story, Doyle allows Watson to incorporate insights from an unspecified point in the future that enhance the reading experience.
