Under the arch of trees the darkness was such that even the edge of the road could not be seen. Not a sound in the forest. Both animals and birds, influenced by the heaviness of the atmosphere, remained motionless and silent. Not a breath disturbed the leaves. The footsteps of the colonists alone resounded on the hardened ground.

During the first quarter of an hour the silence was only interrupted by this remark from Pencroft:--

"We ought to have brought a torch."

And by this reply from the engineer:--

"We shall find one at the corral."

Harding and his companions had left Granite House at twelve minutes past nine. At forty-seven minutes past nine they had traversed three out of the five miles which separated the mouth of the Mercy from the corral.

At that moment sheets of lightning spread over the island and illumined the dark trees. The flashes dazzled and almost blinded them. Evidently the storm would not be long in bursting forth.

The flashes gradually became brighter and more rapid. Distant thunder growled in the sky. The atmosphere was stifling.

The colonists proceeded as if they were urged onwards by some irresistible force.

At ten o'clock a vivid flash showed them the palisade, and as they reached the gate the storm burst forth with tremendous fury.

In a minute the corral was crossed, and Harding stood before the hut.

Probably the house was occupied by the stranger, since it was from thence that the telegram had been sent. However, no light shone through the window.

The engineer knocked at the door.

No answer.

Cyrus Harding opened the door, and the settlers entered the room, which was perfectly dark. A light was struck by Neb, and in a few moments the lantern was lighted and the light thrown into every corner of the room.

There was no one there. Everything was in the state in which it had been left.

"Have we been deceived by an illusion?" murmured Cyrus Harding.

No! that was not possible! The telegram had clearly said,--

"Come to the corral immediately."

They approached the table specially devoted to the use of the wire. Everything was in order--the pile on the box containing it, as well as all the apparatus.

"Who came here the last time?" asked the engineer.

"I did, captain," answered Ayrton.

"And that was--"

"Four days ago."

"Ah! a note!" cried Herbert, pointing to a paper lying on the table.

On this paper were written these words in English:--

"Follow the new wire."

"Forward!" cried Harding, who understood that the despatch had not been sent from the corral, but from the mysterious retreat, communicating directly with Granite House by means of a supplementary wire joined to the old one.

Neb took the lighted lantern, and all left the corral. The storm then burst forth with tremendous violence. The interval between each lightning- flash and each thunder-clap diminished rapidly. The summit of the volcano, with its plume of vapor, could be seen by occasional flashes.

There was no telegraphic communication in any part of the corral between the house and the palisade; but the engineer, running straight to the first post, saw by the light of a flash a new wire hanging from the isolator to the ground.

"There it is!" said he.

This wire lay along the ground, and was surrounded with an isolating substance like a submarine cable, so as to assure the free transmission of the current. It appeared to pass through the wood and the southern spurs of the mountain, and consequently it ran towards the west.

"Follow it!" said Cyrus Harding.

And the settlers immediately pressed forward, guided by the wire.

The thunder continued to roar with such violence that not a word could be heard. However, there was no occasion for speaking, but to get forward as fast as possible.

Cyrus Harding and his companions then climbed the spur rising between the corral valley and that of Falls River, which they crossed at its narrowest part. The wire, sometimes stretched over the lower branches of the trees, sometimes lying on the ground, guided them surely.