Two yeggmen hold up Helen, on night duty at Ferndale, lock her in a closet, and escape. Later, standing on a bridge over the freight yards, Helen sees the two bandits aboard an outgoing freight, and drops onto the roof of the car from above as it crosses underneath. A chase along the roofs of the speeding cars ensues, all of the participants falling into the water as the freight crosses a river. The train is brought to a halt, Helen is rescued, the thieves are arrested, and Helen looks forward to next week's hazard.