Mark, who also serves as an executive producer on the series, has reportedly now begun conversations with the network to return for a handful of episodes as long as they agree to renew the procedural for a 19th season. It's not known how Mark's character Gibbs' stepping back will be written into the show. With ten out of the show's shortened run of 16 episodes down, fans could be in for a dramatic season finale. Could Mark be leaving the cast at the end of season 18? As for what Mark himself has said about leaving the show, he has remained tight-lipped but did tell