When oyster farmer Andie Greatorex is robbed of a bucket of oyster seed worth $35,000, she comes to Julia Snowden for help. Who wants to sink Andie's successful business? Is it a rival oyster farmer, an ex-employee, a neighbor who objects to the oyster cages floating on the beautiful Damariscotta River, a lobsterman who feels pushed out by the farm leases, or someone from Andie's personal life?

Then Andie turns up dead, floating by her dock in the SCUBA gear she wears when harvesting her oysters. Julia's head start puts her in a perfect position to help her friends in the Maine State police major crimes unit with the investigation. But can Julia make sure the right suspect gets sent up the river before she ends up in a watery grave?