Dr. Heidegger invites four old acquaintances to his study to try an experiment. The four guests are a ruined politician, a former merchant ruined by speculation, a man suffering from gout from a life of sinful pleasures, and a woman who remains in seclusion due to scandals. Dr. Heidegger has them drink from a mysterious vase supposedly containing the Fountain of Youth. The four guests revert to youthful appearances and behavior but then start fighting, having forgotten who they are. It is revealed to be an experiment in human folly and the temporary nature of worldly things.