straining face with his little shaft of lantern
light.

She did not speak; but he followed her eyes. They were on the
burnished copper railing refracting the thin light that danced back and
forth across that dungeon-like chamber. He questioned her fixed gaze,
but still he did not understand her. She caught his hand, and retained
it fiercely. He thought, from her pallor, that she was on the point of
fainting, and he would have placed her full length on the hard cement,
but she struggled against it, and still kept her hold on his hand.

Then she took the tiny lantern from his fingers, and bending low,
tapped with it on the cement. Durkin, listening closely, knew she was
sounding the telegrapher's double "I"--the call for attention, implying
a message over the wire.

Slowly he spelt out the words as she gave them to him in Morse,
irregular and wavering, but still decipherable.

"The--railing--is--charged!"

"Charged?" he repeated, as the last word shaped itself in his
questioning brain.

He took the lantern from her hand, and swung the shaft of light on the
glimmering copper. From there he looked back at her face once more.

Then, in one illuminating flash of comprehension, it was all clear to
him. With a stare of blank wonder he saw and understood, and fell back
appalled at the demoniacal ingenuity of it all.

"I see! I see!" he repeated, vacuously, almost.

Then, to make sure of what he had been told, he crossed the room and
picked up the bar of steel that had fallen at his feet as he first
entered the door. This bar he let fall so that one end would rest on
the metal vault-covering and the other on the rail of copper.

There was a report, a sudden leap of flame, and the continued hissing
fury of the short-circuited current, until the bar, heated to
incandescence, twisted and writhed where it lay like a thing of life.
He drew a deep breath, and watched it.

That was the danger he had so closely skirted? That was the fate which
he had escaped!

He stood gazing at the insidious yet implacable agent of death,
spluttering its tongue of flame at him like an angry snake; and, as he
looked, his face was beaded with sweat, and seemed ashen in color.

Then a sense of the dangers still surrounding them returned to his
mind. He shook himself together, and, making a circuit of the room,
found the switch and turned off the current. As he did so he gave a
little muffled cry of gratitude, for across the rea