Jack Minot and Janey Pecq are next-door neighbors and best friends so frequently seen together that Janey earns the nickname Jill after the rhyme "Jack and Jill." Unfortunately, the sweet moniker proves prophetic when a wintry day spent sledding ends in a terrible fall that leaves both young people seriously injured.

While Jack's head wound leaves him fragile for a few weeks, Jill's damaged back keeps her bedridden for months and with limited mobility afterward. Their mothers and friends do their best to make time pass more quickly with songs, elaborately costumed tableaus, and frequent visits. Even as petty jealousy, dreams deferred, and growing pains challenge the friend group, Jack and Jill ultimately grow stronger and closer together in this charming coming-of-age tale.