“True,” said Spilett, “I remember having left it open.”

“A fine job you have made of it, Mr. Spilett,” cried the sailor.

“What is done cannot be undone,” replied Cyrus Harding.  “We must consult what it will now be best to do.”

Such were the questions and answers which were rapidly exchanged between Harding and his companions.  It was certain that the bridge had been crossed, that the shore had been invaded by animals, and that whatever they might be they could by ascending the left bank of the Mercy reach Prospect Heights.  They must therefore be advanced against quickly and fought with if necessary.

“But what are these beasts?” was asked a second time, as the yelpings were again heard more loudly than before.  These yelps made Herbert start, and he remembered having heard them before during his first visit to the sources of the Red Creek.

“They are colpeo foxes!” he exclaimed.

“Forward!” shouted the sailor.

And all arming themselves with hatchets, carbines, and revolvers, threw themselves into the lift and soon set foot on the shore.

Colpeos are dangerous animals when in great numbers and irritated by hunger, nevertheless the colonists did not hesitate to throw themselves into the midst of the troop, and their first shots vividly lighting up the darkness made their assailants draw back.

The chief thing was to hinder these plunderers from reaching the plateau, for the garden and the poultry-yard would then have been at their mercy, and immense, perhaps irreparable mischief, would inevitably be the result, especially with regard to the corn-field.  But as the invasion of the plateau could only be made by the left bank of the Mercy, it was sufficient to oppose the colpeos on the narrow bank between the river and the cliff of granite.

This was plain to all, and, by Cyrus Harding’s orders, they reached the spot indicated by him, while the colpeos rushed fiercely through the gloom.  Harding, Gideon Spilett, Herbert, Pencroft and Neb posted themselves in impregnable line.  Top, his formidable jaws open, preceded the colonists, and he was followed by Jup, armed with knotty cudgel, which he brandished like a club.

The night was extremely dark, it was only by the flashes from the revolvers as each person fired that they could see their assailants, who were at least a hundred in number, and whose eyes were glowing like hot coals.

“They must not pass!” shouted Pencroft.

“They shall not pass!” returned the engineer.

But if they did not pass it was not for want of having attempted it.  Those in the rear pushed on the foremost assailants, and it was an incessant struggle with revolvers and hatchets.  Several colpeos already lay dead on the ground, but their number did not appear to diminish, and it might have been supposed that reinforcements were continually arriving over the bridge.