“I hope you are right, O’Neil,” Phil said, looking gratefully at the cheerful sailorman, “but I fear these men are capable of carrying out their threat.”

Escape was impossible—they were as secure in this prison as if they were in the old Bastile. The footfall of their guards told of their vigilance. The heavy oaken door was doubly barred and locked on the outside.

Their midday meal lay upon the floor untasted by the two lads. Food would have choked them; but O’Neil ate as calmly as if he were aboard ship.

The sounds of life outside came faintly to their ears. They heard the laughter of children playing in the streets, and the rattle of military accoutrements, as soldiers marched along. The heat of their dungeon was almost unbearable and they suffered from lack of water to wash their bruised bodies.

Suddenly they heard the sounds of alarmed humanity; startled cries, a hurrying of many feet, and the clang of iron shod hoofs upon the hard earth.

O’Neil listened intently. Then he sprang to the window near the ceiling of their cell, catching the sill with his fingers and drawing himself up until he could peer through the iron bars.

“What is it?” cried both lads in alarm.

“There’s something going on to seaward,” he answered; “the people are running about like chickens without heads, and the soldiers are moving inland. I wish we could get a sight——”

His next word was lost in a heavy crash and sharp explosion that seemed to shake the building to its foundation.

“Is it an earthquake?” cried Phil, excitedly.