- Tuck Family's Immortality: The prologue introduces the Tuck family and their unique characteristic of immortality, hinting at the central conflict and exploration of the consequences of eternal life.
- Mortality vs. Immortality: Through Winnie Foster's interaction with the horse who is about to be put down, the contrast between mortality and the desire for eternal life is established, setting up the exploration of this theme in the novel.
- Nature and the Woods: The description of the woods, the singing toad, and the natural beauty surrounding Treegap foreshadow the significance of nature and its connection to the Tuck family's immortality.
- Winnie's Curiosity and Adventurous Spirit: Winnie's curiosity and eagerness to explore the woods suggest her inclination towards adventure and hint at her role in uncovering the Tuck's secret.
- The Presence of the Stranger: The mysterious presence of the stranger watching Winnie from the woods hints at the involvement of an external force or conflict that will impact the story's events.
- Danger and Consequences: The foreshadowing of danger and potential consequences of immortality is conveyed through the encounter with the toad whose call warns of trouble, and the ominous line "somehow there was peril in paradise."
- The River: The mention of the river in the prologue suggests its potential significance as a boundary between the ordinary world and the realm of immortality, echoing the theme of choice and consequence that runs through the novel.