The setting gives more of a cautious and for me kind of an unemotional mood. Rainsford is looking at his surroundings wondering what he's going to do, but he really cant do anything Besides sleep.
Answer: The mood is uneasy, perhaps ominous; there is a sense of foreboding.
Explanation: inclusion of details such as the "stealthy steps" outside his room, the "dark and silent" chateau, "black noiseless forms" moving in the pattern of shadow, and the "sallow moon" create a mysterious scene which the protagonist, Rainsford, is sleepless, disturbed by the sounds and sights in his surroundings.
According to this paragraph, I would say that the tone is sad and informal. It could be considered sad because of her personal experience. How she also felt when her first boyfriend left her for another girl.
