Nancy spends a winter weekend on campus--and finds that crime is on the curriculum. Ned invites Nancy, Bess, and George to Emerson College's Winter Carnival for four days of nonstop skiing, skating, and sleigh riding. But a jewel heist on campus puts a big chill on the weekend, and the police believe they have their man--Rob Harper--one of Ned's best friends. Convinced of Rob's innocence, Nancy undertakes an investigation of her own. But the action on ice proves more slippery than she expected. Someone at Emerson is out to teach Nancy a lesson and show her just how dangerous winter sports can be. When it comes to jewelry, some like it hot--and the carnival of crime is heating up fast.