"The Reef" is a novel by Edith Wharton that explores complex human relationships and moral dilemmas. The story revolves around George Darrow, a diplomat, who is engaged to Anna Leath, a widow living in France. His love is put to the test when he encounters Anna's stepson's governess, Sophy Viner, and enters into a brief affair. The rest of the story follows the consequences of this indiscretion, causing tension and mistrust among the characters.