When the third partner in their small Cape Cod trading business dies, Shad Gould and Zoeth Hamilton adopt his little daughter Mary-'Gusta. After several years, the two old salts decide that Mary should be properly educated and send her to an exclusive school in Boston, telling her that her father left her a large fortune. In Boston, Mary meets Crawford Smith, but their happiness together is threatened when she learns that he is the son of Edgar Fuller (alias Smith), a scoundrel who had run off with Zoeth's wife and stolen his money.