It's the first big snowfall of the season in Fruitvale and the Calendar Club has a snow day! Leon is about to run outside to get Dottie and Casey when he notices the back door of his house is open--and there are mysterious footprints in the snow! So the Calendar Club may have the day off from school, but they don't have a break from solving mysteries. Is it possible that Bigfoot has made his way to their town?