A savory sea tale exudes the salty tang and ruddy, weathered atmosphere of Cape Cod. Many little islands surround Saturday Cove, but David and Sally Blake set out in their dory to discover which of these houses the Blake ancestral treasure. Another problem arises for David when he is accused of stealing lobsters from the islanders' traps. In an attempt to prove his innocence, David uncovers the real culprit, Roddy McNeil, who has also been thwarting the Blakes in their hunt for the treasure. During a raging storm David saves the repentant Roddy from drowning, his friend Poke masters his fear of the sea, and Sally unearths the final clue to the, secret of Saturday Cove. The treasure proves commercially valueless and the children comprehend their real treasure is in the islands, the sky and the sea. Colorful regional quality and strong line illustrations emerge through a somewhat routine plot.