Mighty Truck is super strong, super fast... and a super fun babysitter! When Hattie's bulldozer cousins Zip and Beep visit Axleburg, Clarence offers to watch them on his day off. Zip and Beep play tag, kick the can, and jump jumper cables--but no matter how fast they zoom, Zip and Beep just don't run out of gas! How can Clarence keep up with these wheely energetic youngsters? Sounds like a job for Mighty Truck!