The Doctor's run-ins with The Master in the pony dimension seems to be increasing lately. So does his insanity. The Master went from snickering and his classic charm, to twitching and muttering about some pony version of his home planet Gallifrey, that he calls "Gallopfrey". The Doctor figures that it's just a case of his psychotic mind reaching a major break. But is this completely true? The Doctor starts to wonder that himself when he finds something odd in his TARDIS… or should we say, somepony.