After an unsuccessful package-four holiday in Italy, during which she deals ruthlessly with a young Italian Lothario, Sister Carmichael returns to her work in the casualty department of a large general hospital. One of her young nurses has got into trouble and Carmichael, fiercely protective towards her subordinates, broods darkly on revenge. Meanwhile, she has struck up an uneasy friendship with the extrovert Sister O'Hara and together they dabble in spiritualism, which brings uncanny and unexpected results for Sister Carmichael.