Agnes and Ellen Isit, two poor English sisters, unexpectedly inherit from their uncle a rich estate near Naples, complete with big villa and manly Italian majordomo. The latter, Salvatore, makes use of his Latin charm to seduce Agnes, who soon turns from prim spinster to passionate lover. Ellen observes the romance with amusement first before realizing how little considerate Salvatore becomes after marrying Agnes. Worse, Agnes's health starts deteriorating. Worried about her sister, she contacts Dr. Ben Dench, a family friend.