In a lecture hall on October 13, 1927, the speaker, Thursby, welcomes the audience. Although only five inches tall, Thursby is elegantly dressed; also, his head is that of a lop-eared rabbit. An English lop rabbit, to be specific.
Thursby relates a story of long past: In a grand house in the country, six figments of the imagination (specifically nursery figments, also known as Cozies) have gathered on the nursery window seat for a theatrical presentation. The performance, though, is interrupted when the new nanny arrives. From the start, something about the new nanny makes the Cozies worry for the little human in their care—a toddler nicknamed Bingo.
When their worst fears come true, the Cozies must figure out how six imaginary beings can make a difference in the world “out there.”