On a typhoon night in 1970, the maternity ward lost power, and two baby girls were secretly switched...
Everyone in Dongjiao Village sees the little fisher girl Hai Luoluo as "one more mouth to feed." She sleeps under a patched quilt, yet can read the sea's moods at a glance. Half an hour before the tide goes out, she knows which reef crevice hides a big blue crab. The evening before the wind changes, she can look at the clouds and tell you which way the wind is coming from.
She dries shrimp, ferments fish sauce, and raises razor clams. With her adoptive parents, who are always hungry, she turns hard times into the brightest light in the whole village, one account at a time.
But just as their life starts to improve, trouble comes all at once: her aunt sneaks in at night to steal their nets, a lazy man spreads rumors that her family is engaging in speculation, and the head of the supply and marketing cooperative nitpicks her goods and downgrades them. Little Luoluo rushes into the brigade office clutching her ledger and calculates everything line by line, leaving them red-faced on the spot.
Then Shen Shutong, a military wife newly arrived on the island, sees a child with a face just like hers. Her enamel mug clatters to the ground. Her birth parents come looking for her in tears. Should she acknowledge them or not? Just as they begin making arrangements for the reunion, half a page of an old file left behind by the person who switched the babies suddenly comes to light. Someone with powerful connections is seeing red. Can Luoluo still decide the fate of the tides in Dongjiao Fishing Village?