Harding, Pencroft, and Spilett seized their guns and ran out of the house. Top, at the foot of the palisade, was jumping, barking, but it was with pleasure, not anger.

"Some one is coming."

"Yes."

"It is not an enemy!"

"Neb, perhaps?"

"Or Ayrton?"

These words had hardly been exchanged between the engineer and his two companions when a body leaped over the palisade and fell on the ground inside the corral.

It was Jup, Master Jup in person, to whom Top immediately gave a most cordial reception.

"Jup!" exclaimed Pencroft.

"Neb has sent him to us," said the reporter.

"Then," replied the engineer, "he must have some note on him."

Pencroft rushed up to the orang. Certainly if Neb had any important matter to communicate to his master he could not employ a more sure or more rapid messenger, who could pass where neither the colonists could, nor even Top himself.

Cyrus Harding was not mistaken. At Jup's neck hung a small bag, and in this bag was found a little note traced by Neb's hand.

The despair of Harding and his companions may be imagined when they read these words:--

"Friday, six o'clock in the morning.

"Plateau invaded by convicts.

"Neb."

They gazed at each other without uttering a word, then they re-entered the house. what were they to do? The convicts on Prospect Heights! that was disaster, devastation, ruin.

Herbert, on seeing the engineer, the reporter, and Pencroft re-enter, guessed that their situation was aggravated, and when he saw Jup, he no longer doubted that some misfortune menaced Granite House.

"Captain Harding," said he, "I must go; I can bear the journey. I must go."

Gideon Spilett approached Herbert; then, having looked at him,--

"Let us go, then!" said he.

The question was quickly decided whether Herbert should be carried on a litter or in the cart which had brought Ayrton to the corral. The motion of the litter would have been more easy for the wounded lad, but it would have necessitated two bearers, that is to say, there would have been two guns less for defense if an attack was made on the road. Would they not, on the contrary, by employing the cart leave every arm free? Was it impossible to place the mattress on which Herbert was lying in it, and to advance with so much care that any jolt should be avoided? It could be done.

The cart was brought. Pencroft harnessed the onager. Cyrus Harding and the reporter raised Herbert's mattress and placed it on the bottom of the cart. The weather was fine. The sun's bright rays glanced through the trees.

"Are the guns ready?" asked Cyrus Harding.

They were. The engineer and Pencroft, each armed with a double-barreled gun, and Gideon Spilett carrying his rifle, had nothing to do but start.

"Are you comfortable, Herbert?" asked the engineer.

"Ah, captain," replied the lad, "don't be uneasy, I shall not die on the road!"

While speaking thus, it could be seen that the poor boy had called up all his energy, and by the energy of a powerful will had collected his failing strength.

The engineer felt his heart sink painfully. He still hesitated to give the signal for departure; but that would have driven Herbert to despair--killed him perhaps.

"Forward!" said Harding.

The gate of the corral was opened. Jup and Top, who knew when to be silent, ran in advance. The cart came out, the gate was reclosed, and the onager, led by Pencroft, advanced at a slow pace.

Certainly, it would have been safer to have taken a different road than that which led straight from the corral to Granite House, but the cart would have met with great difficulties in moving under the trees. It was necessary, therefore, to follow this way, although it was well known to the convicts.

Cyrus Harding and Gideon Spilett walked one on each side of the cart, ready to answer to any attack. However, it was not probable that the convicts would have yet left the plateau of Prospect Heights.

Neb's note had evidently been written and sent as soon as the convicts had shown themselves there.