  The title: "Fifty Shades of Grey."   This couple was steamy -
in explicit, handcuff-friendly ways.  Since then, millions of
readers have validated James' private fantasies (oh yes, the
author owns up to it) by devouring that first book and the other
two that make up her trilogy, "Fifty Shades Darker" and "Fifty
Shades Freed."  James will appear at Books-A-Million in Katy on
Wednesday, signing books from 7 to 9:30 p.m. The lively Brit
spoke with the Chronicle by phone from her London home.   Q:
Your trilogy had humble beginnings as "Twilight" fan fiction
that you posted on Ultimately, you reworked so much of the story
that it assumed a life of its own. What is it about the "Fifty
Shades" books that touched a cosmic nerve and lured tens of
millions of readers?  A: I don't know! I wrote them for me. They
are my fantasies writ large, which seemed to be other people's
fantasies, too, which made me feel slightly better about the
whole thing.  Q: With U.S. book sales for the trilogy at 30
million (in all formats),