Can Nancy solve this chilling mystery? Who wears a blue scarf and old rubber boots, and has broccoli for a nose? It's Sherlock -- Nancy, Bess, and George's snowman! The girls are thrilled to be on winter vacation and take part in all of the season's activities! Nancy's friend Deirdre has even transformed herself into Madame Chocolata, a fortune-teller who predicts the future by reading hot cocoa marshmallows! But the wintry days get a little too chilly after many of Deirdre's visions come true. Sherlock even goes missing -- just as predicted! Can the Clue Crew put a freeze on this mystery before it snowballs out of control?