Sometime in the past, Maud took Pinkie on a journey, though she doesn't remember when they started or why. All that mattered was that they were moving, over plains of grass, past great forests, across stoney roads and beyond frozen seas. They were always on the move, had seen lands far and wide. There might have been other ponies, too, but they had probably gotten tired of walking just halfway through, settling down in quiet places.

Maud Pie doesn't remember, but it doesn't matter anymore anyway, because she is climbing a mountain now and Pinkie Pie is sick. Now more than ever, her little sister needs her to be strong and she needs to find a doctor before it's too late.