The tone of “The Landlady” shifts from lighthearted to suspicious over the course of the story. The following passage from the first page captures the initial easygoing narratorial tone:
Billy was seventeen years old. He was wearing a new navy-blue overcoat, a new brown trilby hat, and a new brown suit, and he was feeling fine. He walked briskly down the street. He was trying to do everything briskly these days. Briskness, he had decided, was the one common characteristic of all successful businessmen. The big shots up at the head office were absolutely fantastically brisk all the time. They were amazing.
The simple and to-the-point sentences here help convey a lighthearted tone, as does the content of the sentences, which center on young Billy’s commitment to “briskness.” Dahl uses a version of the word “brisk” four times in this one passage to help readers understand how enthusiastic young Billy is. He is, Dahl communicates, a sprightly yet naïve teenager trying to emulate “the big shots up at the head office,” not a self-aware or overly thoughtful adult.
Once Billy meets the landlady and decides to stay overnight at her bed and breakfast, the tone of the story starts to shift into a more suspicious register. This is especially true after Billy notices that the last two guests who signed the landlady's guest book were young men who went missing years ago. This unsettled tone continues until the end of the story when, it becomes clear, the landlady killed and stuffed the two men and is planning to do the same to Billy.