Christmas is fast approaching, so Barney and the kids are quite excited. They help decorate the Caboose for the holidays and build a "thinking" snowman in the park. Then they visit a tree planted by Beth's great-great-grandfather that's now the prettiest, oldest tree in the park. Beth's grandmother is in charge of decorating the tree for Christmas this year, and everyone is shocked to discover the large star to adorn the tree's top is missing! Grammy suggests it's up in her attic and dispatches Barney and the kids there to find it.
