It's Monday again, and for Abigail, Jacob, Zack, and Bo, that means it's time-travel Day! This week the kids can't believe their luck: They're going to meet Walt Disney!

But when they jump back to the past, they discover that Mr. Disney wants to quit instead of making the first animated movie with sound. Abigail and her friends can't let that happen: Without his first movie, there wouldn't be all those other awesome Walt Disney movies or a Disney Channel on TV! But how can the kids get Mr. Disney to follow his dream -- and keep their mission top secret?