Just Call me Lopez requires a balance of reading: suspension of disbelief and imaginatively filling in the gaps are required. Silf imagines a middle-aged woman, Rachel, meeting Lopez (Ignatius of Loyola) at various times over the course of a few months. They converse about life and spirituality.
Silf wants to make Ignatius and his spirituality accessible, even friendly, to readers. As Paul Brian Campbell, SJ, says in the foreword: "I have heard Jesuits nervously joke that they have no fear of coming face-to-face with Almighty God in Heaven, but are filled with trepidation at the prospect of meeting Ignatius of Loyola!...I've noted that his contemporaries--the people who actually were with him and worked alongside him--all seemed to love him and to enjoy being with him." (xi) Accordingly, Silf plays up the human, jocular, humble part of Ignatius: calling him Lopez, imagining him as a self-deprecating, sometimes unsure man whose spiritual eagerness occasionally overtakes wisdom.
This isn't a programmatic introduction to Ignatian spirituality, but rather an imaginative introduction to the man himself that hints at his spiritual legacy, with brief discussions of the Exercises, discernment, consolation/desolation, and so forth. It would be a good reset button for someone too familiar with Ignatian spirituality, and a gentle introduction for someone totally unfamiliar with it or intimidated by it.