In this holiday special, Elmo’s father shares a story from long ago, when Sesame Street is known as the most unfriendly street in town. The tale follows the ancestors of Elmo, Grover, Big Bird, Bert, Ernie, Oscar the Grouch and Cookie Monster as they help bring cheer to a dreary place, setting it on the path to becoming the bright, kind and music-filled street it is today.