Yes, there was the car crash, but it was what was happening behind the scenes that made for the real drama. According to a forthcoming book, How to Save a Life: The Inside Story of Grey’s Anatomy by Lynette Rice, an editor-at-large with Entertainment Weekly, Patrick Dempsey—and his beloved character, Derek “McDreamy” Shepherd—left the show after diva-like behavior. “Some cast members had all sorts of PTSD with him,” remembered executive producer James D. Parriott, who had to be brought back to the show to manage Dempsey and his exit. “He had this hold on the set where he knew he could stop production and scare people.”

The executive producer believes that Dempsey “was just done with the show.” A longtime anonymous crew member said the actor was tired of working long, unpredictable hours, “miserable” with “no one to talk to.” Tensions between him and both lead actress Ellen Pompeo and showrunner Shonda Rhimes didn’t help. Rhimes and Dempsey were “at each other’s throats,” according to Parriott, while Pompeo would get frustrated when Dempsey “would complain that ‘I’m here too late’ or ‘I’ve been here too long’ when she had twice as many scenes in the episode as he did.” Finally, Rhimes gave the network an ultimatum: “If he doesn’t go, I go.”

Another executive producer, Jeannine Renshaw, told Rice, “Nobody wanted him to leave… Patrick is a sweetheart. It messes you up, this business.”