The author explores the rise and long, sad denouement of the man who directed 'Rebel Without a Cause.'Nicholas Ray faced a roomful of film students. They had come to learn from the director who'd made James Dean an icon in "Rebel Without a Cause" and a gunslinger of Joan Crawford in the distaff western "Johnny Guitar." Ray began a mock exercise in filming a scene and the reverential students waited for his instructions — and they waited.