The day is the longest and hottest of the year. Nothing stirs in Treegap, the wood, or the surrounding countryside. Winnie's mother and Granny sit in the parlor in a surprisingly unladylike state of disarray, sipping lemonade. Though Winnie thinks this makes them more interesting, she takes her lemonade upstairs and sits in her rocking chair, after hiding the bottle of water from Jesse. Winnie rocks in time to the ticking of the grandfather clock in the hallway. After supper, Winnie sees that the sky is thickening and the air is growing heavy. She believes it's going to rain, and her family closes all the windows when they go to bed.
The new and interesting way that Winnie's mother and Granny behave on this day shows Winnie that even as these women act separate from the natural world by cleaning, organizing, and staying indoors, they actually are still a part of the natural world. Returning to her rocking chair allows Winnie to gain comfort from something that she doesn't have to explain herself to, as her mother would certainly notice and be suspicious if Winnie were seeking extra comfort from her.
At nine that night, Winnie wanders around her room. She's excited, but she also feels very guilty. She knows that she shouldn't go down to the jailhouse and switch places with Mae and she wonders if her parents will ever trust her again. Around 11 o'clock, Winnie lies down and thinks of Angus, Mae, Miles, and Jesse. She thinks that they seem helpless and too trusting, and they need her help. She turns her thoughts to Jesse and wonders if, when she's 17, she'll really drink the water and if she'll be sorry later. Winnie reasons it's probably not even true and the Tucks are crazy, though she loves them anyway. She falls asleep and wakes up just before midnight.
Winnie's ability to wonder whether her parents will trust her again shows that now, she knows and understands that her actions have consequences and affect more people than just herself. This choice to go down to the jailhouse will have negative consequences for Winnie's family--it will make them look bad, she will look disrespectful, and it's also illegal. However, her recognition that she should do it anyway suggests that acting in the service of friends makes these negative consequences easier to live with.