Tom and Carole are a happy young couple who have everything except good health. While vacationing on Cape Cod they meet Lucinda Hobson, a mysterious woman who deals in herbal teas and claims to possess a potent elixir capable of curing almost any illness and extending life indefinitely. The couple are skeptical, but after taking the elixir Carole feels much better.

Eventually, Tom learns the truth: the elixir does work—most of the time. But he also learns the truth about Lucinda, who clearly illustrates the downside to living so long. Tom’s final confrontation with her leaves his faith shaken to its very core until a chance meeting with an old figure from his childhood results in a profound realization about the true meaning of life, death, faith, and love.