But that wasn’t the only queer thing in the house. the very next day i found out that mrs. brympton had no nurse; and then i asked agnes about the woman i had seen in the passage the afternoon before. agnes said she had seen no one, and i saw that she thought i was dreaming. to be sure, it was dusk when we went down the passage, and she had excused herself for not bringing a light; but i had seen the woman plain enough to know her again if we should meet. i decided that she must have been a friend of the cook’s, or of one of the other women servants: perhaps she had come down from town for a night’s visit, and the servants wanted it kept secret. some ladies are very stiff about having their servants’ friends in the house overnight. at any rate, i made up my mind to ask no more questions.
how does this excerpt support the idea that the story is told by an unreliable narrator?