Leah

Nine or ten years old, no training, no power. She catches Ivy mid-theft and does not let it go.

Her father

The reason she believes in heroes, and the reason the confrontation lands.

LEA: My papa told me about you. He said the heroes saved everyone. He said Noel especially, that Noel could have killed him once but didn't, that Noel chose to protect instead of destroy, and that's why we're alive, my whole family, because Noel chose mercy. (ch. 228)

So Leah's entire family exists because of a mercy Noel extended to a man who had been on the other side. She has been raised on it.

What she does

She walks into a storehouse at night with a lantern, recognises a wanted hero, and then notices the stolen goods in her hand.

LEA: Then what are you doing with their things in your hands?

LEA: You're supposed to be a hero. Heroes don't steal from people.

LEA: You're throwing it all away. Everything they fought for. Everything Noel and Maeve and Johann and all of them gave up.

Then she puts her lantern down and raises her fists.

LEA: If you're not a hero, fight me. Prove you're just a thief who doesn't care about anyone. IVY: I'm not going to fight a child. LEA: Why not? Are you scared?

IVY: This isn't a fight you want. LEA: It's the only one I've got.

What she works out

Ivy deflects every swing for several minutes and never returns one. Leah lands exactly one weak hit, on an opening she makes with words rather than with her fists.

Then she reasons it out on her own:

LEA: You could have hit me. Easily. I'm not stupid, I know I'm not actually good at fighting. You could have hurt me the whole time and you didn't.

LEA: I think it's because you can't. [...] Because you're a hero. Just like Noel. He could have killed my papa and he didn't either. That's what heroes do. They could hurt people and they choose not to. (ch. 229)

That is Act 6's thesis, arrived at independently by a nine year old who was not there. The six were defined at the Festival of Heroes by choosing not to finish each other.

Afterwards

Ivy walks her home, and on the way stops a drunk man who reaches for her. Leah's questions are practical:

LEA: Is he dead? IVY: No. LEA: Will he wake up?

Then, when Ivy says she has realised something:

LEA: So say it.

Ivy cannot, yet. The next afternoon she can, and Leah's response closes the arc:

LEA: That's much better! You're acting like a real hero now!

Open questions

• Whether her father is the man from ch. 181, "The Oath". See ivy.md.
• Her family name. "The Hendricks' storehouse" is named as a target, and "the Hendricks' home" is where Ivy walks her, which reads as the same household but is not stated to be hers.