Dodo realized that her incompetence was pissing off the viewers at home, so she decided to do the logical thing and let WOTAN skullfuck her, giving her gonorrhea in the process. Afterward she sent Hartnell a note saying "lol bye!" and the show was no longer ruined. Ben and Polly were brought in to fill the companion void. Enjoy them while you can here, because you'll never see them again after this.