The Ski Slope Mystery

SOMEBODY'S NOT PLAYING FAIR!
Nancy, Bess, and George are going skiing. But the whole weekend is getting crazy. First some bratty boys play catch with Bess's hat. Then George's lucky necklace disappears!
Not only that, but someone's getting very pushy on the mountain. It's up to Nancy to find out who's playing all the dirty tricks. Because someone's turning the snow fun into no fun at all!