Cyrus Harding, Gideon Spilett, Herbert, and Pencroft were to repair to the corral, and if they did not find Ayrton, search the neighboring woods.

At six o’clock in the morning, the engineer and his three companions had passed Creek Glycerine, and Neb posted himself behind a small mound crowned by several dragon trees, on the left bank of the stream.

The colonists, after leaving the plateau of Prospect Heights, immediately took the road to the corral.  They shouldered their guns, ready to fire on the slightest hostile demonstration.  The two rifles and the two guns had been loaded with ball.

The wood was thick on each side of the road and might easily have concealed the convicts, who owing to their weapons would have been really formidable.

The colonists walked rapidly and in silence.  Top preceded them, sometimes running on the road, sometimes taking a ramble into the wood, but always quiet and not appearing to fear anything unusual.  And they could be sure that the faithful dog would not allow them to be surprised, but would bark at the least appearance of danger.

Cyrus Harding and his companions followed beside the road the wire which connected the corral with Granite House.  After walking for nearly two miles, they had not as yet discovered any explanation of the difficulty.  The posts were in good order, the wire regularly extended.  However, at that moment the engineer observed that the wire appeared to be slack, and on arriving at post No. 74, Herbert, who was in advance stopped, exclaiming,—­

“The wire is broken!”

His companions hurried forward and arrived at the spot where the lad was standing.  The post was rooted up and lying across the path.  The unexpected explanation of the difficulty was here, and it was evident that the despatches from Granite House had not been received at the corral, nor those from the corral at Granite House.

“It wasn’t the wind that blew down this post,” observed Pencroft.

“No,” replied Gideon Spilett.  “The earth has been dug up round its foot, and it has been torn up by the hand of man.”

“Besides, the wire is broken,” added Herbert, showing that the wire had been snapped.

“Is the fracture recent?” asked Harding.

“Yes,” answered Herbert, “it has certainly been done quite lately.”

“To the corral! to the corral!” exclaimed the sailor.

The colonists were now half way between Granite House and the corral, having still two miles and a half to go.  They pressed forward with redoubled speed.

Indeed, it was to be feared that some serious accident had occurred in the corral.  No doubt, Ayrton might have sent a telegram which had not arrived, but this was not the reason why his companions were so uneasy, for, a more unaccountable circumstance, Ayrton, who had promised to return the evening before, had not reappeared.  In short, it was not without a motive that all communication had been stopped between the corral and Granite House, and who but the convicts could have any interest in interrupting this communication?