An alarming epidemic has broken out in the vineyards of which Leonard Sheldon is the manager, and in answer to his wire that a doctor be sent to the little Mexican settlement at once, Katherine Torrance, a young and beautiful physician, is sent. Accompanying her is her younger brother, Clifford, weak-willed and dissipated. The inhabitants of the village are ignorant and superstitious and the situation is a grave one. Upon Katherine's arrival, Sheldon, thunderstruck that a woman should tackle such a job, tries to persuade her to return, but this she declines to do and goes about her duties, faithfully caring for the afflicted. The light which she wears on her forehead in order that she may see clearly into the throats of her patients, arouses the suspicion of the benighted Mexicans, and as the disease spreads, the trouble is accredited to this light, or "evil eye," and the medicine which she leaves is thrown away. The friendship of Leonard and Katherine is rapidly ripening into love, ...