The engineer has seen the lower pyramid of rocks on the track and has whistled "down brakes."
The train is stopping; it will be saved, for one of the two obstructions will derail the motor-car.
Sister Martha starts to run down the track. She has not taken a dozen steps when the juggernaut dashes into the pyramid of rocks.
Instantly there is a flash and an explosion, that shakes the mountain.
Great ledges of rock slide from the overhanging crags.
In a shower of splintered stone, Martha is literally entombed. Her life is sacrificed on the altar of devotion. She has lived a Christian and dies a martyr.
But the Keystone Express is saved.
Its passengers and crew, when they recover from the fright occasioned by the explosion, hasten from the cars. Trainmen are sent up the track to investigate. Brakemen are also sent down the track to carry the news to the station.
One of these men stumbles across Widow Braun. He returns to the train carrying her.
From her, Trueman and the other passengers, including the Coal and Iron Police, learn of the plot to wreck the train and of the heroic effort made by Sister Martha and the widow herself, to avert the calamity.
Trueman starts in quest of Sister Martha. Accompanied by one of the trainmen with a lamp, he reaches the scene of the explosion.