Sesame Street's newest muppet, fairy Abby Cadabby, falls asleep and follows a Red Rabbit (Elmo) down a rabbit hole and in to a "Wonderland," where she encounters quirky and whimsical characters including Tweedle Dee and Tweedle Dum (Bert and Ernie) and The Cheshire Cookie Cat. She also attends a silly tea party presided over by a Mad Hatter (Grover) who also can be a "sad" hatter or a "glad" hatter with the change of a hat. Will Abby find her missing magic wand and be able to get back to Sesame Street, or does the Grouch of Hearts (Oscar) have other plans?