“They’re on to us!” he vociferated.  “Somebody’s got wise—­they’re—­”

Little red spurts of fire began to jet, among the buildings; the crackling of shots started popping, like corn-kernels exploding.  Dark figures were racing for the Palisade gate—­the gate where, if any slightest thing went wrong with track or giant plane, the whole vast fabric might crash down, a tangled mass of wreckage.

Then it was, that for the first time in all his knowledge of the Master, Bohannan heard the strange man laugh.

Joyously he laughed, and with keen pleasure.  His eyes were blazing, as he thrust the rising-plane lever sharply up.

More shouts volleyed.  From somewhere back there in the body of the ship, a cry of pain resounded.

Bohannan flung the window-pane to one side, and blazed away like mad at the attackers.

A shatter of broken glass burst into the pilot-house.  Alden, catching his breath, quivered.  He uttered no outcry, but his right hand went across and clutched his wounded left arm.

“Got you?” cried the major, still pumping lead.  He paused, jerked Alden’s automatic from its holster and thrust it into the captain’s hand, now red.

Alden, a bit pale but quite impassive, opened fire through the jagged hole in the double pane.  Accurately the captain fired at dark figures.  One fell.  Another staggered; but as the machine swept on, they lost sight of it.

Men rose up before the rushing airship.  One of the great gates began to swing shut, far at the end of the track.  The Master laughed again, with the wind whipping at his hair.  “Full speed ahead!” he shouted into the telephone.

The Nissr leaped into a swifter course.  Then all at once she skidded clear of the track, slanted upward, breasted the air.  Her searchlight blazed.  All along her flanks, fire-jets spangled the night.  Cries echoed from her, from the great stockade.

The Master gave her all the lift the farthest wrench of the levers would thrust on her.  The gate was almost shut now—­would she clear it?

Below, track, earth, everything was spinning in and in.  Ahead, above, yawned vastnesses.  The Master could no longer see the gate.  A second of taut thrill—­

Crash!

The Nissr quivered, staggered, yawed away.  The forward starboard float had struck.  A faint yell rose as someone, hurled backward by the shattered debris of the gate, plunged down the cliff.

For half a second, the giant plane reeled over the abyss.  Her rush and fury for that half-second threatened to plunge her, a mangled, flaming wreck, hundreds of feet down on the black, waiting rocks below the Palisades.

But engine-power and broad wings, skill of the hand at the levers, and the good fortune that watches over bold men, buoyed her again.

Suddenly she lifted.  Up at a dizzy angle she sped.

A thing of life, quivering, sentient, unleashed, the gigantic Eagle of the Sky—­now in heroic flight toward the greatest venturing ever conceived by the brain of man—­steadied herself, lifted on the wings of darkness, and, freed from her last bonds, leaped quivering and triumphant into the night.