Don Drapkin was once one of Ron Perelman's closest associates. A former lawyer at Skadden, Arps, Drapkin spent 20 years working for Perelman's holding company MacAndrews & Forbes as his chief dealmaker and "strategic thinker." He was so close to Perelman, in fact, that the billionaire mogul once likened him to a brother. Until, that is, Drapkin jumped ship in 2007 and joined Lazard as the firm's vice chairman at the invitation of Lazard chief Bruce Wasserstein. The split seemed uncharacteristically amicable at the time—Perelman announced that Drapkin had "done a terrific job," and he'd "miss him." But the relationship seems to have taken a turn for the worse since then. Perelman just hit Drapkin with a lawsuit.