Elmo is excited to play a messy scientific game show called, "What Happens Next?" with Oscar as the host! With the help of his adult friends on "Sesame Street", Elmo learns lots of new things about what would happen next if, for example, Slimey jumps into a little mud pool from a low diving board, and then from a high board. Would there be a little splash or a big splash? Elmo uses fun science words such as hypothesis when making guesses about what would happen next. Elmo has a great time learning to observe, making guesses, and checking to see if his hypothesis is correct!