She was one of the authors that I followed as a child--meaning that I deliberately sought out everything she'd ever written. Even then, one thing I especially liked about her was that she did NOT write series (and I say that even as someone who also read every Black Stallion book ever penned). In fact, when she did eventually write a sequel to
The Egypt Game, I hated it.

From her obituary linked below:
She modeled her characters in "The Egypt Game" on some of her students at Washington School but turned down the book's transformation into a movie. "Disney wanted to option it for a film but wouldn't guarantee a multiracial cast," her longtime editor Karen Wojytla said in an interview. "She was very forward-thinking, and wouldn't sell them the rights."http://www.latimes.com/local/obituaries/la-me-zilpha-keatley-snyder-20141019-story.htmlOne of the authors who made a lifelong Reader out of me.