One day, Elmo and Abby spot their friend Bert reading a book about scientists. Elmo quickly comes up with an idea -- he and Abby will become scientists. For their first experiment, they want to figure out if everyone on Sesame Street takes a bath. From Ernie with his rubber ducky to Oscar with his trash can, there is an adventure around every corner. And what do they discover during their experiment? You'll just have to read to the end to find the answer.