Although it is a dangerous job, Faith Sutton has been keeping the lighthouse beacon burning on her own ever since her father died five months ago. Her mother, however, would rather Faith learn to dress and act like a proper lady, so she moves the family back into town. Faith is heartbroken. Not only must she leave behind the beauty of the Lake Superior coast and the memories it brings of her father, she must surrender the job she loves to Nat, who doesn't seem to grasp the grave responsibility of the position.

Once in town, Faith tries hard to please her mother and assures her she won't return to the lighthouse. But when a fierce storm strikes while her mother is out sailing, Faith must choose between breaking this promise or risking her mother's life to the inexperienced hands of the new keeper.