Dr. Heidegger, an eccentric old man, invites four of his friends to meet in his study. Mr. Medbourne had once been a wealthy merchant, but had lost all his fortune by a “frantic speculation,” and was now little better than a beggar. Colonel Killigrew had wasted his best years on sinful pleasures, which had contributed to various illnesses. Mr. Gascoigne had once been an infamous politician, but now was simply obscure. Widow Wycherly had once been a beautiful lady, but, scandalous stories of her youth had turned the town against her and driven her into seclusion. Each of the male guests had, at one point in time, been lovers of Widow Wycherly, and had once competed to win her to the point of “cutting each other’s throats for her sake”.
Mr. Heidegger’s study is described as a curious place, a dim chamber filled with strange objects: a skeleton, a looking-glass that purportedly revealed the Doctor’s deceased patients, a portrait of a woman whom the Doctor was once to marry before her tragic and untimely death, and a black book filled with magic. On the particular summer afternoon of the tale, a small, round table rests in the center of the room. Placed upon the table is a glass vase, as well as four champagne glasses.
The Doctor asks his friends to aid him in an experiment. He takes an old, withered rose from the black book of magic, a rose he professes bloomed fifty-five years prior. He threw the rose into the vase, and as it lay upon the surface of the water, it regained its original bloom. Dr. Heidegger explains to his friends that the water is from the Fountain of Youth. His friends are skeptical, and Colonel Killigrew asks what effect the water might have on a human being. The Doctor invites his friends to try the water, but declines participation, saying, “Having had much trouble growing old, I am in no hurry to grow young again”. Before they drink, he warns them: “Think what a sin and shame it would be, if, with your peculiar advantages, you should not become patterns of virtue and wisdom to all the young people of the age.” His friends, who had come to regret and repent the missteps of their youth, laugh at the thought that they would ever go astray again.
The guests drink, and immediately see a difference – each person appears healthier, brighter, and livelier. They demand more water, impatient to grow even younger, until they were again in their prime. However, their aged figures reflected in the Doctor's mirror hint that their newfound youth is merely a delusion. The widow, dancing flirtatiously, asks the Doctor to be her partner. The doctor defers to the other three men, who eagerly gather around the Widow, now a young and beautiful woman once more. They begin to fight with each other for her attention, until, “grappling fiercely at one another’s throats”, they knock over the table and shatter the vase holding the Water of Youth.
The doctor’s friends find themselves old again. The Doctor professes that his friends have taught him an important lesson: that even if the fountain were to gush at his doorstep, he would not drink from it, even if the delirium it allowed lasted for years instead of moments. His friends, however, had not learned this lesson. Instead, they resolve to travel to the Fountain of Youth.
During their youth, the four "venerable" friends gave into their various vices. Now wizened in old age, they laugh at the idea that they would commit the same follies if given another opportunity to be young. However, with one taste of Dr. Heidegger's youth serum, they do exactly that. Hawthorne's use of the word "venerable," one author writes, must be ironic, as the characters do not demonstrate the seriousness that the word conveys.
Some have argued that their transient experience of youth was a mere delusion, as Hawthorne hints with the words “fancied,” “seemed,” “intoxicating,” and “deception” that the elixir of youth was only, perhaps, champagne or liquor. Regardless of the nature of the fluid, it produced an effect that, real or not, revealed a simple message: people rarely learn their lessons, and may only repeat the same mistakes when given the opportunity to relive the past.
Though Dr. Heidegger's guests' appearances were (perhaps) changed by the water, their characters were not. Dr. Heidegger as well remains unchanged by the events. He touches his beloved's rose when it returns to its withered state, proclaiming to love it in its decrepit condition just as he had admired its bloom. The rose, a symbol of both his fiancee and her death, cannot bring back Sylvia's life nor restore Dr. Heidegger's innocence. The old man's sorrows cannot be erased by a magical elixir and thus he refuses the charms of the water. Just as his friends' true, flawed natures are exposed by his "experiment", the Doctor's wisdom reveals itself.
From a historical perspective, the characters in the story can also be linked to real people. Thomas Killigrew and William Wycherley, for example, were Restoration writes of “bawdy comedies”. Wycherley had "incurred the ill feeling of Charles II and languished seven years in prison, unable to pay off the debts he had run up as a man of fashion". Gascoigne in the story is a "man of evil fame," and George Gascoigne, an English writer of comedy, was once charged with crimes such as manslaughter and atheism. Matthew Medbourne, an actor who died in prison in 1679, was involved in "frantic speculation," just as the character Medbourne in the story. Finally, the name Heidegger can also be found in stage history. John James Heidegger, Manager of the King's Theater for George II, was charged in 1729 for promoting vice and immorality. In a sense, the Heidegger in Hawthorne's story also promotes vice, by enabling his friends to relive sinful times. Again, Hawthorne employs fact in his fiction to promote his message to his readers through familiarity.