“Treachery! treachery!” screamed Pereira. “The reeds are fired, and that witch has betrayed us.”

“Ha! ha! ha! ha!” cried Otter again from his airy perch. “Treachery! treachery! And what if the slaves are loosed? And what if the gates be barred?”

Hitherto the mob had been silent in their fear and wonder. There they stood closely packed, a hundred or more of them, staring first at Otter, then at the advancing flames. Now they found tongue.

“He is a fiend! Kill him! Storm the slave camp! To the gates!” they yelled in this language and in that.

For many it was their last earthly cry, since at that moment a sheet of flame burst from the rampart of the camp, followed by the boom of the cannon, and six pounds of canister swept through the crowd. Right through them it swept, leaving a wide lane of dead and dying; and such a shriek went up to heaven as even that place of torment had never heard.

Then they broke and fled this way and that, screaming curses as they went.

When Leonard and the priest had rolled down the rising bridge they found Juanna standing safely by the guard-house, surrounded by some of the Settlement men.

“To the gun!” he cried, “to the gun! Fire into them! I will follow you.”

Then it was that he saw Otter left to his death and called out in fear. But Otter saved himself as has been told, and clambered down the bridge safe and sound.

Leaning on the dwarf and Francisco, Leonard, followed by Juanna, staggered along the earthwork to the place where the gun was mounted. Before he had gone a step he caught sight of the figure of Soa, outlined in bold relief against the background of the fire and surrounded by many of the freed Settlement men. At the instant when he saw her she was in the act of springing back from the breech of the gun, the lanyard in her hand. Then came the roar of the shot and the shriek of the smitten.

“Wow!” said Otter, “the old woman has not been idle. She is clever as a man, that one.”

Another minute and they were helping to reload the piece, that is, except Soa, who was on her knees kissing Juanna’s hands.

“Come, stop that!” said Leonard, sinking to the ground, for he was utterly exhausted. “Those devils have gone for their arms. They will try to storm us presently. Is the shot home, Peter? Then run her out, sharp; and you, Soa, screw her nose down.” Next he bade the freed slaves arm themselves with stakes or anything that they could find, for of rifles they had but four, two of which they had found in the guard-house.

Presently the slavers came on with a yell, carrying long planks, by the help of which they hoped to cross the dike.

“Look out!” said Leonard, “they are going to open fire. Under the earthwork, every man of you!” And seizing Juanna who was standing near, he pulled her down into cover.

It was not too soon, for next instant a storm of bullets swept over them. Most of the men had understood and taken shelter, but some were too slow or too stupid. Of these one fell dead and two more were hit. Soa and Peter alone took no heed, and yet they remained unhurt. There stood the woman, while the bullets whistled round her, laying the gun as coolly as though she had served in the Royal Artillery, and with her was the head-man, Peter. Peter was shot through the waist-cloth and a ball cut its way through Soa’s grizzled hair, but neither of them seemed to notice these trifles.

“They are mad, Baas,” cried Otter, who was watching the enemy over the top of the embankment. “See! they are coming across the open.”

Leonard looked. The dwarf was right: in their rage and hurry the slavers, half hidden in a cloud of smoke caused by their rapid firing, were advancing across the clear space instead of creeping along the edge of the dike. What was more, the necessity of carrying the planks caused them to pack in groups. Soa gave a final twist with her lever and waited, her hand on the lanyard. A bullet cut it in two, but without firing the gun, and she grasped the shortened cord.

“Now for it!” cried Leonard, as the first party came into the line of fire.

Soa sprang backwards with a yell: again the piece thundered out, and the canister screamed through the air. It tore along the advancing files, then, striking the beaten earth, rebounded and caught those who were following with the ricochet, and with awful effect. Whole groups were mowed down by this one discharge, the destruction being twice as large as that caused by the first shot, for at this greater range the canister found room to spread. Also the rebounding missiles flying hither and thither among the crowd did no little execution. Down went the men in heaps, and with them the planks they carried. They had no more wish to storm the slave camp; they had but one thought left, the thought of safety, and the survivors of them fled in all directions, yelling with fear and fury.

“Load up, load up!” cried Otter, lifting the charge of powder which lay at hand. “They will try to break open the gates and get out, then they will cut us off.”

As he spoke they saw many men run from the auction-shed to the water-gate. But it could not be climbed, the key was gone, and the massive bolts and beams were not easy to break. So they brought hammers and a tree-trunk which had supported an angle of the shed, and battered at the gate. For two minutes or more it held, then it began to give.

“Swift! swift!” cried Otter again as he dragged at the cannon to turn it, “or all will yet be lost.”

“Hurry no man’s ox, Black One,” said Soa, as she laid the gun with the help of Peter.

A cry went up from the slavers; the gate was tottering, but it still held by the upper hinges. A few more blows and it must surely fall. But those blows were never struck. Again Soa sprang backwards, and the roar of the gun was answered by the screams of the slavers as the shrapnel ploughed through them.

Of those who were left the most part fled for shelter to the auction-hut and to the Nest itself. Some ran across to the magazine, but appeared to be unable to enter it, for soon they were seen flying back again, while about a dozen of the boldest remained at the gate trying to complete its destruction. On these Leonard and Otter opened fire with rifles, but it was not until three or four of them had fallen that the rest fled to join their companions beneath the shelter of the sheds.

“Oh! look, look!” said Juanna, pointing to the east.

It was indeed a spectacle never to be forgotten.

The dense reeds, measuring twelve to fifteen feet in height, had been fired far to the east of the Nest, and as the wind gathered to a gale and the fire got firmer hold, it rolled down upon the doomed place in billows and sheets — a sea of flame that sometimes spouted high into the air and sometimes ran swiftly along the ground.

The reeds crackled and roared like musketry as the fire ate into them, giving out thick volumes of smoke. At first this smoke had passed above the spectators, now it blew into their faces, half choking them and blotting out the sky, and mixed up with it were showers of sparks and fragments of burning reeds brought forward on the wind.

“The house and sheds will soon catch now,” said Leonard; “then they must take refuge in the open spaces, where we can deal with them,” and he nodded towards the gun.

As he spoke tongues of flame darted into the air, first from the thatch of the shed, then from the roof of the Nest. They were afire.

“We must be careful, Baas,” said Otter, “or the slave-shelters behind us will burn also, and all those in them.”

“Heavens! I never thought of that,” answered Leonard. “Here, Father, if you wish to do a good work, take some of these people and the buckets they use to water the slaves. Let three or four men get on to each roof and extinguish the sparks as they fall, while others bring them water from the moat.”

The priest sprang up and set to the task, at which he laboured gallantly for two long hours. Had it not been for his efforts, the sheds and the slaves in them must have been burnt, for the sparks fell thick upon the dry thatch, which caught again and again.

Now the sights and sounds grew more and more fearful. Maddened with fear, the remainder of the slave-drivers and their servants rushed from the flaming buildings, striving to escape from the fire. Some flung themselves desperately into the aloes and prickly-pears on the inner rampart, and, climbing the palisade beyond, escaped into the marsh, while some collected on the open space, and at these the gun was fired from time to time when the smoke lifted. Others again ran to the dike of the slave camp begging for mercy, there to be shot by Otter, who never wearied in his task of revenge. From behind them also rose the hideous cries of the slaves, who believed that they were about to be burned alive, and screamed as they dragged at their manacles.

“Oh, it is like hell!” said Juanna to Leonard, as she buried her face in the grass that she might see no more, and to escape the suffocating smoke. She was right.

So the time went on. One by one the roofs of the v............