Book excerpt: In August 1995, after the Walt Disney Company announced its $19 billion merger with Capital Cities/ABC, Michael Orvitz's power as head of the high-rolling Creative Artists Agency seemed eclipsed--until he joined Michael Eisner at the top of the Disney empire. This book offers the first complete, unauthorized portrait of one of the richest, most formidable, yet least known of the media moguls, whose clients include Tom Hanks, Brad Pitt, David Letterman, and Barbra Streisand. of photos.