CHAPTER TWENTY THREE.
A STRANGE NIGHT'S LODGING.
Mike shrank from attempting to penetrate farther into the narrow hole; but Vince's determination was contagious, and, in obedience to a jog of the elbow, he followed his companion, as, with the lanthorn held high enough for him to look under, the cudgel in his right-hand, he began to wade on, finding that the passage twisted about a little, very much as the tunnel formed by the stream did--of course following the vein of mineral which had once existed, and had gradually decayed away.
To their great delight, the water, at the end of fifty yards or so, was decidedly shallower; the walls, which had been almost covered with sea anemones, dotted like lumps of reddish green and drab jelly, only showed here, in company with live shells, a few inches above the water, which now, as they waded on, kept for a little distance of the same depth, and then suddenly widened out.
Vince stopped there, and held up the lanthorn, to see the darkness spread all around and the light gleaming from the water, which had spread into a good-sized pool.
"Mind!" cried Mike excitedly: "there's something coming." He turned to hurry back, but Vince stood firm, with his cudgel raised; and the force of example acted upon Mike, who turned towards him, grasping the conger bat firmly, as the light showed some large creature swimming, attracted by the light.
But the boys did not read it in that way.

Their interpretation was that the creature was coming to attack them; and, waiting till it was within reach, Vince suddenly leaned forward and struck at it with all his might.
The blow only fell upon the water, making a sharp splash; for the lad's movement threw the lanthorn forward, and the sudden dart towards the animal of a glaring object was enough.

The creature made the water surge and eddy as it struck it with its powerful tail, and went off with a tremendous rush, raising a wave as it went, and sending a great ring around to the sides of the expanded cavern, the noise of the water lapping against the walls being plainly heard.
This incident startled, but at the same time encouraged the lads, for it gave them a feeling of confidence in their own power; but as soon as they recommenced their advance, there was another shock,--something struck against Vince's leg, and in spite of his effort at self-command he uttered a cry.
There was no real cause for alarm, though; and they grasped the fact that the blow was struck by one of a shoal of large fish, or congers, making a rush to escape the enemies who had invaded their solitude, and in the flurry one of them had struck against the first object in its way.

"I'm sure they were congers," whispered Mike.

"I felt one of them seem to twist round me." "Never mind: they're gone," replied Vince.