"“The least sound would be fatal to our plans.”..."See in text(The Adventure of the Speckled Band)
Doyle’s subtle diction here elevates the atmosphere of dread and anticipation. The use of “fatal” here is figurative but in the reader’s mind it triggers a sense of death.
"and what of the very peculiar words of the dying woman..."See in text(The Adventure of the Speckled Band)
Note that Holmes does not specifically quote the "very peculiar words" about the speckled band. It is intentional that the “words” are vague, as will be seen later in the story.