Mrs. Adamson lives on an Island in the sea with her husband and their four boys. Fishing is important on this Island, but Mrs. Adamson, being a newcomer to the Island doesn't know a lot about fishing, or about haddock or halibut. A gift of fresh halibut from Mrs. Adamson's neighbour, her husband's experience as a fisherman and her son's reading bring her to the wonders of halibut - a strange shape-changing fish and how it is quite different from haddock