why did abby leave ncis

Abby Sciuto, played by Pauley Perrette, left NCIS primarily because of behind- the-scenes conflicts, especially a falling out with series lead Mark Harmon. The conflict reportedly began after Harmon brought his dog onto the set, which bit a crew member, causing tension. Perrette felt unsafe and ultimately decided to leave the show, stating she was "terrified of Harmon" and had nightmares about him attacking her. In the show, Abby's character exit was portrayed with a dramatic assassination attempt. After surviving the attack, Abby resigned from NCIS to move to London and start a charity in honor of her late colleague, Clayton Reeves, who died protecting her. Abby's final episode was Season 15, episode 22, titled "Two Steps Back".