Disney Channel‘s brand new original series Andi Mack is available today on-demand via the Disney Channel App and all other digital retailers, but J-14 has all the scoop on what you can expect from the show, including the major plot twist. WARNING: If you don’t mind spoilers, keep reading, but if you don’t want to know what happens, stop reading now.

What is Andi Mack about?

Andi Mack is a compelling story of self-discovery written by Terri Minsky, the creator of the ever-so-popular series Lizzie McGuire, and stars newcomer Peyton Elizabeth Lee as Andi Mack.

What happens in the first episode of Andi Mack?

Andi is a normal girl whose life gets turned upside down when her free-spirited older sister, Bex, returns on the day before her 13th birthday. Upon Bex’s arrival, it becomes clear that there are family issues between Bex and her mother.

In spite of their mother’s wishes, Bex shares stories from her adventures with Andi by digging through a small box containing photos and items from her time away from home. Andi is intrigued by all of Bex’s stories and admires her sister’s edgy lifestyle.

After spending some time together, Bex sets up a frisbee lesson for Andi, with her crush Jonah, played by Asher Angel. Andi discovers that Jonah has a girlfriend and tells Bex that she does not know anything about her because she has not been in her life.

Okay, now really stop reading if you don’t like spoilers because we are about to reveal arguably the biggest plot twist ever on a Disney Channel Original Series.

What is Bex’s big secret?

Later that night, Bex goes into Andi’s room and opens her memory box. She shows Andi a photo of herself holding a baby. Andi is confused at first, but Bex eventually reveals she is not Andi’s sister — she’s her mother! The family dynamic completely changes and Andi is forced to figure out how to deal with the shocking news, while confronting Jonah’s girlfriend, Amber, played by Emily Skinner. It’s a good thing she has her friends Cyrus Goodman, played by Joshua Rush, and Buffy Driscoll, played by Sofia Wylie.

How did the Andi Mack cast react?

In the video below, Peyton EXCLUSIVELY told us that she only found out about the twist after multiple auditions, and Sofia revealed that her jaw was basically on the floor when she found out.

Watch the first episode below. Let us know what you think in the comments section!