Morris is a young boy with a vivid imagination, and his favorite thing to do is wear the tangerine dress from his classroom's dress-up center. However, his classmates don't understand his love for the dress. They insist that dresses are only for girls and make it clear that he isn't welcome in the spaceship they are building, arguing that astronauts don't wear dresses.
One day, feeling isolated and hurt by their teasing, Morris's mother allows him to stay home from school. While at home, he dreams of an extraordinary space adventure with his cat, Moo. Inspired by this dream, Morris paints a breathtaking scene and decides to bring it to school with him. Determined to share his vision, he constructs his own spaceship, decorates it with his painting, and invites two of his classmates to join him on an adventure in outer space.