harm the Keystone. No, it will stop here."

Another and another rock is placed on the rails.

She knows that these boulders are a poor impediment to a wildcat car;
but they are the only things available.

A whirring sound rings in her ears. It is the car rolling down the grade
with the velocity of a thunder-bolt.

In a minute or two at the most, the car will be upon her.

Still she does not falter. The second pyramid must be completed.

Again she turns to look down the track. The headlight of the engine
seems to be upon her. It is, in fact, just crossing the culvert.

A glance at the pile of rocks makes them appear insignificant.

"They will never be able to stop the car," she moans.

Then with a final effort she tugs at a boulder larger than any of the
others. She has it on the rail when the whistling of the engine startles
her.

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.

The trainman discovers the body of Martha.

Bending over the prostrate body Harvey Trueman weeps. It is the manly
expression of deep emotion.

"She died to save my life and the lives of the hundreds on the train.
Was there ever a more noble sacrifice? It cannot be that she has given
her