内容简介：
Ta-ra ta-ra ta-ra-ra-ra ta-rat Professor Krenner took the silver bugle from his lips while the strain echoed flatly from the opposite, wooded hill. That hill was the Isle of Hope, a small island of a single eminence lying half a mile off the mainland, and not far north of Freeling. The shore of Lake Huron was sheathed in ice. It was almost Christmas time. Winter had for some weeks held this part of Michigan in an iron grip. The girls of Lakeview Hall were tasting all the joys of winter sports. The cove at the boathouse (this was the building that some of the Lakeview Hall girls had once believed haunted) was now a smooth, well-scraped skating pond. Between the foot of the hill, on the brow of which the professor stood, and the Isle of Hope, the strait was likewise solidly frozen. The bobsled course was down the hill and across the icy track to the shore of the island.