As little Bunny goes into his Great Green Room, the mantle clock announces it is seven o’clock and time for bed. The kind Old Lady reads to him from the book, Goodnight Moon. She reads of the wonderful things there, and Bunny says hello to them all: the telephone, the red balloon, the cow jumping over the moon, the three bears on chairs, two little kittens with a pair of mittens, clocks, socks, a little toy house, a mouse, a comb and a brush, and a bowl full of mush.
Bunny wants to play with each one. He still has lots of energy! The Old Lady whispers “hush” and takes up her knitting in the rocking chair. She tells Bunny to say his prayers and go to sleep. Bunny closes his eyes in his bed, but strange noises capture his attention. The Old Lady playfully tucks him in tight and wishes him sweet dreams.
Bunny, however, is still not ready for sleep, and asks for his dolls. The Old Lady brings all of them to his bed and sings him a goodnight lullaby. She goes back to her knitting. Now the fire in the fireplace, the rocking chair, the kittens and even Mouse keep Bunny awake. Bunny asks for a glass of water. As the Old Lady fetches one, more sounds of clocks and animals arouse Bunny’s imagination and he gets out of bed.
The Old Lady returns with water and asks who has mussed up Bunny’s bed. He answers, “nobody,” and they sing about this famous character no one ever sees who seems to take the blame for so many things. Bunny starts playing with the balloon string and somehow he and Mouse end up entangling the Old Lady in her yarn. She demands that they stop this pandemonium!
Bunny asks about the picture on the wall, The Runaway Bunny. The Old Lady explains that it shows Bunny’s grandmother fishing while Bunny’s father splashed as a little boy in the river. He had told his mother he wanted to run away. Bunny and the Old Lady sing about a boy who wants to run away and an old lady who will always know how to find him and hug him tight.
Bunny seems soothed and ready to settle into bed now. The Old Lady turns off the lamp, says “goodnight,” and leaves the Great Green Room. However, the lamp turns itself on, more strange sounds emerge, and the Moon rises higher into the sky. What’s more, the picture of the cow jumping over the Moon comes to life. The Cat, the Dog, the Dish and the Spoon show up to cheer on Clarabelle the Cow, but her jump falls flat.
Bunny is wide awake now as the entire room seems to come alive with lights and sounds. The telephone rings for Bunny and a scary growl comes over the line. From out of their picture, the Three Bears enter the room, singing and dancing. They do a bunny hop with Bunny and conclude with a tap dance and a game of musical chairs. The Bears try to get Bunny to go to sleep, promising to return the next night, but Bunny has noticed that he has a loose tooth. Mama Bear ties the knitting yarn to his tooth and the other end to a doorknob. She slams the door and Bunny, proud and relieved, shows us his first lost tooth!
Once again, Clarabelle the Cow and her friends come to life in their picture. Bunny tries to show them his tooth, but they sing a song celebrating Clarabelle’s jumping prowess. Despite this encouragement, her second attempt falls flat.
Bunny climbs into bed. The bed and its covers seem to want to envelop him. Escaping, he goes to the toy house which has lit up again with strange chattering. Mouse tells him that some new folks have just moved in. Bunny shows her his tooth and they both sing about the excitement of losing and growing back teeth.
The Old Lady comes back to try to put a stop to the recurring pandemonium. Noticing Bunny’s lost tooth, she gets some paper to wrap it up for the Tooth Fairy. Mouse and Bunny do their best to tape the tooth up without taping themselves together and the Old Lady puts it under Bunny’s pillow. She hushes everyone and everything in the room and leaves to make some tea, expecting Bunny to be asleep on her return.
Bunny and Mouse only pretend to sleep, hoping to remain awake to see the Tooth Fairy. Their play snoring soon turns into actual snoring, however. Tooth Fairy takes Bunny’s tooth and leaves a dime along with a song.
Bunny and Mouse wake up and notice the toy house has lit up once again. Opening it up, they see that it is the Tooth Fairy’s workshop where fairies are turning teeth into stars. Mouse sings of the shining North Star that leads wanderers safely home as Bunny watches the starry night sky outside his window.
Left to his own devices again, Bunny spends time exercising his imagination, turning the Old Lady’s rocking chair into a car, a plane and even a horse in the Wild West. Clarabelle’s friends return and she gets ready for a third attempt to jump over the Moon. Her friends tell her to believe in herself and sing of the positive attitude necessary for success. This time Clarabelle jumps all the way over the Moon to the applause of all.
Now the Moon speaks to Bunny, saying he will shine gently down on him and always be his friend. Bunny notices how quiet things have become. The dolls on his bookcase sing him a lullaby. The Old Lady comes back and Bunny says he is still not tired, but she convinces him it really is time to say goodnight. Bunny says goodnight to Mouse, to the Old Lady and to all the strange and wonderful things in the Great Green Room. And, of course, to the Moon.