The Treegap authorities want to hang Mae Tuck because she killed the man in the yellow suit.

When the man threatens to make Winnie use the spring and take her away to use as proof of what it can do, Mae Tuck is enraged. She declares that he won't take Winnie, swings around with her shotgun, and hits him like a club. He hits the ground right as the constable rides up.

The constable warns them that if the man dies, Mae will go to the gallows. However, she won't be able to die. The Tuck family is immortal because of their spring. If they try to hang her, everyone will know the secret they've worked hard to keep hidden. That's why the have to break her out and run away from the town after the man dies.