For all its search and puzzle, ["The Minnow Leads to Treasure" (published in Britain as "Minnow on the Say")] is no one-dimensional mystery yarn. Here are real people…. There is a villain, but his villainy stems from obtuseness rather than cold-blooded wickedness. And the other grown-ups are all rounded characters, each of whom has an essential function in the dénouement. There are drama and old, remembered heartache in the story, but it is as if it had happened "all on a golden afternoon, full leisurely∗∗∗."… [One] sees and almost smells the garden and fields and shares the joys of exploration and discovery.
Ethna Sheehan, "Search on the River Say," in The New York Times Book Review (© 1958 by The New York Times Company; reprinted by permission), May 4, 1958, p. 32.