Braid Beard and his pirate crew return to retrieve the treasure they buried in Jeremy Jacob's backyard, but first they must help calm his baby sister, Bonney Anne, whom they awoke from her nap.

"Month by month, parents and families of all sorts watch the baby-to-be grow, from a sweet pea to a mango and eventually to a pumpkin--until finally, the babies are born as their wonderful little selves. "--

Helping her parents with the new twins, JoJo must figure out a way to tell the identical babies apart.