American actor Patrick Dempsey was apparently not the most popular actor on the set of Grey’s Anatomy.

The actor has been accused of creating terror on the set of the hit ABC medical drama, as revealed in the new book, How to Save a Life: The Inside Story of Grey’s Anatomy, by EW’s editor-at-large Lynette Rice.

An excerpt of the book published by The Hollywood Reporter, cited the show’s former executive producer James D. Parriott, detailing how Dempsey ‘terrorized the set’ during the later seasons.

"Some cast members had all sorts of PTSD with him. He had this hold on the set where he knew he could stop production and scare people,” said Parriott.

Creator and former showrunner Shonda Rhimes was “protective” of Dempsey’s character of Dr. Derek Shepherd, but when the cameras weren’t rolling, the two were “at each other’s throats,” according to Parriott.

Moreover, the book revealed that star of the show Ellen Pompeo also had issues with the actor, as revealed by former co-executive producer and writer Jeannine Renshaw to the author. As per Renshaw, Pompeo was “frustrated” with Dempsey at the end of his time with Grey’s Anatomy.

"She would get angry that he wasn't working as much. She was very big on having things be fair. She just didn't like that Patrick 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,” Renshaw said.