The Cloudbabies are hard at work. Bobo and Fuffa race through the sky together, going 'choo choo' and pretending to be the Skytrain. As they zoom past, they cause Baba Blue to drop his toolbox and Baba Yellow to smudge Rainbow's stripes. She tells Fuffa and Bobo off and the two of them go off in a sulk. Fuffa sits in the sky and watches as big clouds drift over the horizon. She asks Rainbow where they are going, and he explains that they are moving on and that one day she may do too. As Rainbow leaves, Fuffa thinks moving on would a brilliant idea as she could then play 'choo choo' whenever she pleased. She descends to the Cloudyhouse and tells the Cloudbabies that she will be leaving. They all stand in shock. Lined up to say goodbye, Fuffa agrees to have Baba Pink escort her some of the way. Bobo White soon follows and they stop by Little Star to say goodbye. He's too sleepy to understand what is going on.
