The kids are playing with glass marbles, until one of them rolls away! It was Nick's "extra luck never miss marble”, now what is he going to do? Cat will take them to a sandy beach that's full of marbles! But when they get there, all they see is sand. Cat's friend Sharky McGee explains that sand makes glass. He shows them how sand is turned into glass and all the wonderful things you can make with it. Including marbles!