What is the author's style in From the Mixed-Up Files of Mrs. Basil E. Frankweiler by E. L. Konigsburg?

This tale begins in the form of a letter by Mrs. Basil E. Frankweiler to her attorney, Saxonberg. It continues on in chapter format but is clearly meant to be a file that she has enclosed with her letter detailing a mystery unveiled by Claudia Kincaid and her younger brother, Jamie.

In each chapter, Mrs. Frankweiler makes comments to Saxonberg which appear in parentheses. In this way, readers will get to know Mrs. Frankweiler even though she doesn't experience the story first-hand; her thoughts about the adventures of Jamie and Claudia as well as her disdain for Saxonberg are evident throughout.

The novel begins with a prologue from Mrs. Frankweiler but it isn't until Chapter 9 that readers meet her face to face. Each chapter has an illustration that blends well with the prose and gives young readers a view of what Jamie, Claudia, and even Mrs. Frankweiler look like. Even some of the museum exhibits are drawn and this lends further interest to the book.