At the beginning of the novel, the Tucks have not aged for eighty-seven years. They detail the story of their immortal origins to Winnie, telling her of how they found the spring in the woods and all drank from it out of thirst. It took them a while to realize the effects of the spring, and as time passed, the immortality took its toll on their lives.
Being pursued by people interested in their secret and losing family members because of their longevity, they decided to hide their secret and keep separate, returning to reunite with the family every ten years. It has been many cycles of departing and reuniting by the point the events of the novel take place, and the Tucks have resisted aging for eighty-seven years.