Trigger Hicks, a proud but poor and barely literate mountain girl, takes in wash but dreams of a finer, more romantic life for herself.  She is indifferent to the criticisms of her superstitious neighbors, who mistake her intense religious faith and bad temper for signs of witchcraft.  When the Construction Company arrives in the region to build a dam, Trigger attracts the amorous attention of John Stafford, the married assistant engineer, whose supervisor, George Fleetwood, disapproves of his deceptive romancing.

Inspired by a pack of Bible cards that she has stolen from the local Sunday school, Trigger snatches a sickly, neglected baby from a neighbor's house and carries him to George's cabin, where she prays over him and nurses him back to health.  John, hearing of the abduction, finds Trigger at George's cabin and continues his flirtation, not revealing to her his marriage.  When John's wife appears, however, John is unmasked, and Trigger is heartbroken.  Concerned for Trigger's safety, George convinces her to relinquish the child and return him to his now frantic parents.

When the child falls ill again and eventually dies, an angry mob shows up at Trigger's shack and accuses her of witchcraft.  Although George and John try to subdue and reason with the stone-throwing mob, Trigger is forced to agree to leave town.  The next day, as she packs her few belongings, her faith in herself and in God and prayer shattered, George arrives at her shack to say goodbye.  Touched by her simple devotion, George convinces Trigger not to give up her faith, and makes her promise to meet him at the shack a year from that day, come what may.