Why did Watson not sleep very well that first night ? Chapter 6

Watson describes the bedrooms as seeming newer the rest of the house, and the dining room as having a somber atmosphere. Feeling the same way, Sir Henry comments that he understands why Sir Charles grew so anxious in such a place. That night, Watson does not sleep well. In the dead of night, he hears a woman's sob, and listens carefully for more. However, no more noise comes.