Theories have abounded about her identity, ranging from the Mystery Girl as Barry and Iris’ future daughter to Mystery Girl as The Thinker in another body.
A smaller (although certainly not insignificant) plot has followed the Mystery Girl who first debuted in the gigantic “Crisis On Earth-X” crossover event.
Barry and Iris’ daughter.
Fortunately for those fans who have been dying to know more about her, the finale revealed that Mystery Girl is none other than Nora, a.k.a.