The narrator is a chronically isolated man. A misfit in his own family, he strikes up a friendship with a boy, David, whom he meets in Kensington Gardens one day. As they grow closer to one another, the narrator becomes increasingly perturbed at the idea of abandonment, believing that one day David, too, will grow up and leave him behind. He starts wishing he were David's dad.
Observing David's home life, the narrator notices how David's mom, Mary, is secretly pawning her jewelry in order to support her son because her husband is struggling at work. The narrator starts sending small gifts for David, signing them Mr. Anon. He also strikes up relationships with both the mother and the father separately, although he is careful to not give away his preference for Mary. When Mary finds out the narrator is the donor, she thanks him profusely, but the situation is awkward afterwards.
The narrator tells David that babies used to be birds in Kensington Gardens. Desiring to reunite with his past life as a bird, David sneaks out of the nursery one night and wanders into the park alone. He's flying, a power he's discovered by believing in himself. He meets a man named Solomon who instructs him in the lore of babies in parks. Eventually David wants to return home, but he is stuck in a fenced off corner of the park because he has lost belief in himself and can no longer fly. Trapped here, he befriends various animals before he eventually regains the courage to return home. He's disturbed to see his mother has a new baby now and refuses to announce his return. David finds the narrator once more, and they form their own alternative family as father and son.
