During the train journey from Sherlock's office to the manor at Stoke Moran, Watson is struck by the jarring contrast between the beautiful weather on the one hand, and the sinister murder that he is investigating on the other. Here, situational irony heightens the ominous mood of the story. Watson describes the weather as follows:
It was a perfect day, with a bright sun and a few fleecy clouds in the heavens. The trees and wayside hedges were just throwing out their first green shoots, and the air was full of the pleasant smell of the moist earth. To me at least there was a strange contrast between the sweet promise of the spring and this sinister quest upon which we were engaged.
The beauty of the landscape seems perverse given the disturbing nature of Julia Roylott's murder; the rich natural imagery here would be a fitting backdrop for a picnic—not a murder investigation. Moreover, it is notable that the natural imagery here focuses on new life, especially in its description of the "first green shoots" and "sweet promise" of the spring. By contrast, Sherlock and Watson's investigation is concerned with death. By establishing this troubling contrast, the story generates situational irony, which only heightens the reader's sense of foreboding.
Through Sherlock's use of verbal irony, the story reveals his dry wit. Faced with the threat of Roylott retaliating against Sherlock and Watson for meddling in his affairs, Sherlock tells his companion:
I should be very much obliged if you would slip your revolver into your pocket. An Eley's No. 2 is an excellent argument with gentlemen who can twist steel pokers in knots. That and a toothbrush are, I think, all we need.
Sherlock tells Watson to bring his revolver on their trip to the manor at Stoke Moran because it will provide protection from Roylott's brute strength. His comment is an example of understatement, a form of verbal irony: a revolver, of course, is much more lethal than a counter-argument. Moreover, a man powerful enough to "twist steel pokers into knots" is unlikely to be deterred from inflicting violence by a convincing counter-argument. In addition, Sherlock's comment accentuates the danger that he and Watson will be in if they end up in a physical struggle with Roylott: if a revolver gets involved, people could die. In this way, by understating the danger in which he and Watson would find themselves if they were to confront Roylott head-on, Sherlock conversely accentuates that danger.
