Emily solves the mystery in Hazelmoor after finding Captain Trevelyan's ski boots hidden in the chimney, and two pairs of skis in different sizes. Major Burnaby is the killer. He engineered the table movements during the séance to make the spirit convey the message that Captain Trevelyan had been murdered. Instead of walking the six miles in two and a half hours after the séance, he went to his own house to put on skis, and skied the distance in about 10 minutes. He killed Captain Trevelyan at about a quarter to six. Then he cleaned his skis and put them in the cupboard. He hid Trevelyan's ski boots in the chimney to prevent the police seeing them, and thus possibly realising how quickly a person on skis could have travelled between Sittaford and Exhampton. Major Burnaby hoped that the second pair of skis, of a different size, would pass unnoticed.
