In the prologue to Cimino, Charles Elton’s new biography of Michael Cimino, the author describes pulling up to his subject’s mansion in the Hollywood Hills, knowing full well that the director would not be home. Elton showed up at the mansion’s doorstep in 2018, a year and a half after the director’s death at the age of 77 from undisclosed causes. He was there to sift through the artifacts of a career that changed the course of American movie history even as it also, to some extent, has become lost to it