Life in their rented summer cottage on Seacrow Island is sometimes happy, sometimes exciting, and sometimes tragic, but never uneventful for a Swedish author, his three sons, and nineteen-year-old daughter.
Having decided that it is backward day, a boy dresses himself first in his coat, last in his socks, and continues in that way with the cooperation of his family.
When seven-year-old Mary's father puts her beloved cat, Thomasina, to sleep, Mary stops speaking to him and becomes gravely ill until Lori, a woman rumored to be a witch, restores Thomasina to health and Thomasina saves Mary.
The exploits of mischievous ten-year-old Edie spending the summer on the Massachusetts seashore in the 1910s with her siblings and step-siblings while their parents are in Europe.