The Sign Invisible Feb 18, 1918

Dr. Robert Winston loses faith in himself and his religion when his own mother dies under his scalpel. Abandoning his profession, he moves to the Canadian Northwest, where he avoids companionship and drinks constantly. Despite Robert's atheism, he attracts the interest of Jeanette Mercier, the minister's daughter, and under her gentle influence, he is slowly regenerated. In the meantime, an Indian named Lone Deer bids a temporary farewell to his sweetheart Winona, whose father wishes to die among his own people, but when he finds her canoe overturned in the water, he assumes that she has drowned. Later Lone Deer saves Jeanette from Lou Baribeau, the brutal and lecherous company agent, but is seriously wounded in the struggle. Rev. Mercier convinces Robert to operate, and because the procedure proves successful, the doctor regains his faith and marries Jeanette. Winona finally returns to aid in Lone Deer's recovery.