will return. Oh, may _you_--may _you_!"

"What is written on the Book of Fate, will be," he answered. "Our petty
hopes and fears are nothing, Catherine. If death awaits me, it will be
sweet; for it will come, tonight, in the supreme service of the human
race! Good-bye!"

With a sudden motion, the girl took his face between her hands, and
kissed his forehead. For all her courage and strength, he sensed her
heart wildly beating and he felt her tears.

"Good-bye, Gabriel," she breathed. "Would I might go with you! Would
that my duty did not hold me here! Good-bye!"

Then he was gone, gone with the others, into the thickening obscurity of
the fog-shrouded evening. Now Catherine stood there alone, head bowed
and wet face hidden in both hands.

As the little fighting band disappeared, back to the girl drifted a few
words of song, soft-hummed through the dusk--the deathless chorus of the
International:

"Now comes the hour supreme!
To arms, each in his place!
The new dawn's International
Shall be the human race!..."

CHAPTER XXXIV.

THE ATTACK.

"Halt! Who goes there?"

The challenge rang sharply on the night air, outside a small gate in the
barricade of the Monck Aviation Grounds.

"Liberty!" answered Gabriel, pausing as he gave the password.

"All right, come on," said a vague figure at the gate. The little group
approached. The gate opened. Silently they entered the enclosure.

Another man stepped from a hangar. In his hand he held an electric
flash, which he threw upon the newcomers, one by one.

"Right!" he commented, and took Gabriel by the hand. "This way!"

Ten minutes later, all of them were in the air, save only Gabriel, who
insisted on staying till his entire squad had made a clean getaway. Then
he too rose; and now in a long, swift line, the fighting squadron
straightened away to north-eastward, on the twenty-mile run to Niagara.

The night was foggy, chill and dark. All the aviators had instructions
to fly not less than 2,500 feet high, to keep a careful lookout lest
they collide, and to steer by the lights of the great Air Trust plant.
For, misty though the heavens were, still Gabriel could see the dim glow
of the tremendous aerial search-lights dominating Goat Island--lights
of 5,000,000 candle-power, maintained by current from the Falls,
incessantly sweeping the sky on the lookout for just such perils as now,
indeed, were drawing near.

Momently, as he flew, Gabrie