Beautiful and wealthy young socialite Iris Carr is used to being at the heart of her social group, but when her friends' raucous and unsociable behaviour escalates whilst on holiday in the Balkans she resolves to seek out some tranquillity and travel home alone. But her expectations of peace are short-lived when, at the railway station, Iris wavers in the scorching heat and constant jostle of passengers, fainting suddenly on the platform. She wakes in time to be rushed onto the train, but with a pounding head and a feeling of being almost in a dream. Whilst in this malaise she is comforted by an older English lady called Miss Froy, but when Iris falls asleep she awakes to find Miss Froy has gone and her fellow passengers denying she ever existed.