Everyone is getting ready for a merry Christmas on Sesame Street, when Oscar the Grouch asks Big Bird a very disturbing question: How does Santa Claus, "who is built like a dump truck," get down all those skinny little chimneys? With the help of all his Sesame Street friends, Big Bird attempts to solve the Santa Claus riddle, and in the process discovers that the true miracle of Christmas is the spirit of loving and sharing.