In the midst of a series of unexplained accidents and mysterious coincidences, sixth-graders Calder, Petra, and Tommy lead their classmates in an attempt to keep Frank Lloyd Wright's famous Robie House from being demolished.

Mary W. Chase died on Nantucket Island just over one hundred years ago, but she is still there, in the house she once lived in, and she wants to keep it that way--but first she must somehow contact a group of children who are interested in preserving historic homes on the island.

When thirteen high-value pieces of art are stolen from a secret museum, Calder, Petra, and Tommy are grouped with two new companions to solve puzzles that are complicated by the clever Mrs. Sharpe.

Having run away with her younger brother to live in the Metropolitan Museum of Art, twelve-year-old Claudia strives to keep things in order in their new home and to become a changed person and a heroine to herself.