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Thus a more rounded Holmes or Watson (or Falstaff) is found in a later work depicting a younger person. We don't see how that can justify extending the expired copyright on the flatter character. A contemporary example is the six Star Wars movies: Episodes IV, V, and VI were produced before I, II, and III. The Doyle estate would presumably argue that the copyrights on the characters as portrayed in IV, V, and VI will not expire until the copyrights on I, II, and III expire.