J.M. Barrie, a struggling playwright, encounters a widowed mother, Sylvia Llewelyn Davies and her four sons in Kensington Park. As Barrie befriends the family, he is inspired by their adventures, particularly Peter, who is reluctant to play due to his grief. Barrie helps him to learn to play again and becomes inspired to create a new art form: children's theatre. But who will pay to see a play about children? Who will play these characters? And how will they make Peter Pan fly?