Newcomer Peyton Elizabeth Lee stars as Andi Mack, a girl whose life goes from routine to roller coaster overnight. In the serialized story, Andi is contemplative and artistic and sheltered by overprotective parents. But on the eve of her 13th birthday, Andi's free-spirited older sister Bex returns home with a revelation that changes everything and sends Andi on an uncharted course of self-discovery. At least she's in good company; her best friends, Cyrus and Buffy, are also figuring out their places in the world. Along the way, Andi learns that sometimes the unexpected is what makes life great.