Although Jess initially dislikes River, she experiences constant physical reactions to him that symbolize her deeper feelings. These feelings remain hidden until Jess gets to know River and slowly accepts and explores her physical attraction—which she finds “inaccessible and deeply aggravating” (101) at first. The first time Jess touches River—when she grabs his arm at Twiggs—she feels “physical pressure on her chest” (18). During subsequent interactions, she becomes “light-headed” (117), gets “goose bumps” (125), feels like she’s “melting” (146), and experiences “deep vibrations” and “woozy” spells (162). Although Jess doesn’t respond when the San Diego Union-Tribune journalist asks her and River if they have an “internal reaction” (161) to each other, the truth is that she does. Eventually, Jess’s reactions—and sexual fantasies—become impossible to deny. When Jess and River kiss at the Grubers’ cocktail party, it “shifted the trajectory of them” (204) and reveals that her physical reactions have been indicative of deeper feelings all along.

The roller-coaster that Juno builds for her art-science project symbolizes Jess and River’s tumultuous journey to settling down together. As Juno begs Jess to let her build a model roller-coaster, the latter increasingly feels like she’s on one. Once Jess and River move past their first impressions of each other, they find themselves falling in love.