Speaking of the series, I'm going to level with you -- L'Engle's Time Quintet (which begins with A Wrinkle in Time) can be a challenge when it comes to readers' advisory. First, there's the issue of age range: while the first three books fit comfortably in the upper-middle-grade range, the two following books skew towards YA. Then, there's the fact that the series was published from 1962-1989, and some of the content hasn't aged particularly well. Are these facts RA dealbreakers? Not necessarily. But keeping them in mind might help you to guide enthusiastic new Wrinkle in Time fans toward their next read.