Lila and James Pines had to make a decision to save their children, but only one could survive. Mabel Pines grew up a happy life with her Grunkles. Everything was easy for her and she had lots of friends but she's been having strange dreams about a boy who looks like her. A nameless boy lived a hard life as a slave in the underworld being abused by various masters. He never complained. He always smiled. But all that changed when Bill Cipher met the boy.