When Laura arrives at the blind school, she and Mary enjoy reminiscing about old times in front of the fire while the storm continues outside. They're startled when someone bursts into the house out of the rain. It turns out to be Nels Olsen, just making sure they're alright. He urges them to lock the door, which they do. Moments later, a knock is heard at the door. Assuming it is Nels returning for something, Laura opens the door wide and is horrified to be seized by a strange man. A trio of men burst into the school, one of whom has been shot and is badly wounded. They are members of the notorious Brandywine gang, and they hold Mary hostage while forcing Laura to go find Doc Baker. They warn her that Mary will be hurt if she tries to bring anyone else back to the house.
Laura goes to find Doc Baker, but he's gone out on a call. Nels is in the sitting room listening to Nellie "vocalize" at the piano. Laura hides the truth from Nels when he asks if everything is alright, and instead heads for home to find Pa. Charles tells Albert to stay put and runs out to the blind school.
Posing as Dr. Baker, Charles prepares to operate on the criminal. As he is working, the real Dr. Baker arrives, informed by Nels that Laura was looking for him. When the leader of the gang learns that they've been fooled, he knocks out Doc Baker and holds Mary hostage. Charles has managed to incapacitate the other criminal, but is forced to drop his gun in order to preserve Mary at the hand of the gang leader. Mary takes the opportunity to make her move and shove her captor's shotgun out of Pa's range. Charles narrowly misses getting shot, and a game of cat-and-mouse ensues as he tries to hide from the murderous villain. As Charles hides out in one of the bedrooms, he watches as the doorknob slowly turns. Thinking it might be his daughter, Charles opens the door, only to be shot by the gang's leader. Assuming him dead, the leader moves on to find and victimize Mary.
Not knowing what has happened to her father, Mary calls out in terror to him. She gets no response, but quickly runs to hide when she hears footsteps coming down the stairs. The brutish gang member stalks her throughout the house, finally tracking her down in an isolated room. As Mary struggles to keep the door closed, he easily pushes it open. Preparing to assault her, the man drops his gun and takes a step closer. At that moment, Pa bursts in, his face bleeding, and drags away the would-be assailant. As her tormentor tries to come through the door one more time, Charles breaks a chair across his head, knocking him out and bloodying his mouth. Mary screams as she feels a man's hands laid on her, but is calmed upon hearing her father's voice.
As the Ingalls are reunited after their terrifying night, Laura helps revive Doc Baker, who promises with humor never to make "house calls" again.
When Caroline, Harriet, Adam, and Hester Sue return from their trip, everyone is dismayed to learn that they were denied the grant money. Just as they are discussing how to tighten their belts, an officer comes in and asks what they intend to do with "the bank draft." There was a thousand dollar reward for the Brandywine gang, and everyone celebrates the news that they'll finally have funding.
Meanwhile, the Brandywine brothers are chained and hauled away in a paddy wagon.