As "Sesame Street" starts its eleventh season, Maria is setting out on a big trip to her native country of Puerto Rico for her twenty-first birthday, and taking Olivia with her. Unbeknownst to her, but not to Olivia, the rest of her friends have secretly followed them to Central America to join the celebration. During the day, they keep recruiting the people they meet to pose as them and make Maria think she's seeing things. They don't ultimately make their presence known until the end of the day, when the party begins. The show is brought to you to today by the letter A and the number 2. While all the excitement in Puerto Rico is going on, Kermit the Frog is doing a news report on the elves and the shoemaker, and Edith Ann of "Rowan and Martin's Laugh-In" tells Herry Monster about what makes her proud. Little Jerry and the Monotones perform their big hit "Telephone Rock", Grover watches The Amazing Mumford perform a subtraction trick with pineapples, and Simon Soundman has trouble communicating with the owner of a music store that he wants to buy a trumpet. There are some memorable bits on animation in this episode too, such as the pinball count, with vocals from the Pointer Sisters, and the classic Madrigal Alphabet.