This full-length episode includes popular learning segments such as Elmo's World, Letter of the Day, Number of the Day and Global Grover. Telly has just joined the "Letter of the Month Club," and he is so excited! Vinnie (Seth Green) begins delivering Telly's letters, but they take over Hooper's store where Alan is preparing for a birthday party. There are too many letters! What will happen? This complete episode also focuses on being happy, including how to say "happy" in Spanish. Grover returns from Hawaii to explain how children get ready for a hula party. This episode is brought to you by the letter R and the number 18.