It's Bubblefest on Sesame Street and Alan and Chris are the leaders of the festivities. Telly is excited since he has never blown a bubble before. Everyone starts blowing bubbles but when Telly gives it a try, he blows way too hard and is unable to make a bubble. At this time, Alan and Chris announce that it is time for a Bubble Mix Mystery, which is figuring out how to make the perfect bubble mix. Alan and Chris explain that there are three different ingredients in the bubble mixture (water, soap, and corn syrup). Elmo and Abby have to figure out how much of each ingredient to mix together. They can use a large cup, medium cup, or small cup to measure the amount of each ingredient. After testing the mixtures, Abby and Elmo determine that the mystery mixture consists of water in the largest measuring cup, soap in the medium measuring cup, and corn syrup in the smallest measuring cup. Now, they must solve r a Bubblefest riddle: "What's round and wet, is something that you blow, and has all the colors of the rainbow?" After talking it through, Elmo and Abby figure out that it's bubbles! Alan and Chris demonstrate that bubbles are iridescent and are all colors of the rainbow. Afterwards,Alan and Chris announce a Bubblefest Pop Quiz. They place all kinds of items on a table and Elmo and Abby must figure out which ones they can use to blow bubbles with. For the Bubblefest Finale, Abby and Elmo use a hula hoop to create a bubble using so big, a child can fit inside!?? And Telly finally blows a bubble, too. The crowd cheers and Bubblefest comes to an end.