When the young American Frederick Winterbourne meets his compatriot Daisy Miller in the garden of a grand hotel in Switzerland, he is struck by her beauty, but slightly unsettled by her open ways and her flirtatiousness. Undeterred by this and by his aunt´s disapproval, he invites her to join him in a jaunt to a nearby castle, little suspecting that this will set in train a sequence of events that promises to be a source of heartache and disappointment for him, and threatens to compromise his own social acceptability...