Note: Set on the California coast (presumably northern) where siblings Tom and Jennifer twice visit their grandmother. The sequel may be non-genre. It is listed without comment in The Encyclopedia of Fantasy and not covered in Kirkus Reviews. 2. The Mysterious Christmas Shell (1961) Open Library OL26303361M, LCCN 61-9281, OCLC 1420686 "Sea Meadows, the expanse of cliff and beach and redwood groves long owned by the Vinings" is destined for development as "houses and shopping centers -- unless they could find a missing will. When Jennifer finds a beautiful shell on the beach the clues start unraveling. ..." --1st ed., inside jacket flap viewed at Open Library