Twilight Sparkle is asked to travel to the dimension of the setting of Portal and Portal 2: Aperture Sciences Labratories. GLaDOS wants to test her to see if she really is adept at puzzle-solving and if Twilight can actually teach her something about friendship. When Twilight arrives, she becomes human, and must survive the 19 test chambers, with the promise of cake. But she is aware of the dangers ahead, and the one question that really haunts her is, is the cake a lie?