It’s been a year since Pauley Perrette left 'NCIS' after a 15-season run, and fans want her character Abby Scuitto to come back. The actress says it's never happening , and in a series of tweets over the weekend , Perrette revealed she’s “terrified” of Mark Harmon, her longtime former co-star who plays Gibbs, and that her fear prevents her from ever considering a return to the popular series. She tweeted: "I am terrified of Harmon and him attacking me. I have nightmares about it." She also tweeted graphic photos of what she claimed to be an 'NCIS' crew member with stitches and facial bruising, and she says it happened at the hands of star Harmon. Some reports say the trouble between Perrette and Harmon could be traced to a 2016 incident in which Harmon’s rescue dog attacked a crew member on set. The crew member needed emergency medical attention. There has been no comment from Harmon.