From the Mixed-up Files of Mrs. Basil E. Frankweiler: 35th Anniversary Edition Anniversary edition

Claudia knew that she could never pull off the old-fashioned kind of running away.... She didn't like discomfort.... Therefore, she decided that her leaving home would not be just running from somewhere but would be running to somewhere. To a large place, a comfortable place, an indoor place, and preferably a beautiful place. And that's why she decided upon the Metropolitan Museum of Art in New York City.
-- from From the Mixed-up Files of Mrs. Basil E. Frankweiler
When Claudia decided to run away, she planned very carefully. She would be gone just long enough to teach her parents a lesson in Claudia appreciation. And she would go in comfort -- she would live at the Metropolitan Museum of Art. She saved her money, and she invited her brother Jamie to go, mostly because he was a miser and would have money.
Claudia was a good organizer and Jamie had some ideas too; so the two took up residence at the museum right on schedule. But once the fun of settling in was over, Claudia had two unexpected problems: She felt just the same and she wanted to feel different; and she found a statue at the Museum so beautiful she could not go home until she discovered its maker, a question that baffled the experts, too.
The former owner of the statue was Mrs. Basil E. Frankweiler. Without her -- well, without her, Claudia might never have found a way to go home.
For thirty-five years E. L. Konigsburg's story has entranced readers of all ages. This special anniversary edition contains a new afterword from the author, along with a few extra surprises to delight readers old and new.