<p>TheDoctorfacestheendofhislifeastheMaster’splanshurtleoutofcontrol.Withthesoundofdrumsgrowinglouder,andanancienttrapclosingaroundtheEarth,theDoctorandWilfmustfightalone.Butsacrificesmustbemade,andthedeadlyprophecywarns:"Hewillknockfourtimes."</p>