as he plodded on
cautiously, with his feet sometimes sinking in the bog, sometimes
finding it pretty firm.

But there was no answer; and though as far as was possible Dick walked
in the direction of the sound, the guidance was of the most
unsatisfactory nature, and at the end of a minute or two they listened
again.

"It must be that Thorpeley regularly bogged," said Dick at last, and a
curious shiver ran through him. "I hope he hasn't sunk in."

"He couldn't," said Tom. "I know this part. It's all firm ground
between the water and the track to the sea."

"I can't quite make out where we are," said Dick, staring about him.

"I can. There's the big alder clump, and beyond it there's the river
wall." [Mud embankment.]

"So it is. Yes, I know now. Why, it is all firm about here, and nobody
could be bogged unless he got into a hole. Ahoy!"

He shouted once more, but there was no answer; and when he raised his
voice again it was only for the sound to seem to come back, just as if
they were shut up in some large room.

"He must be hereabout," said Dick.

"Shall we find our way back to the boat?" said Tom in a doubting tone.

"I don't know, but if we don't we could walk home in half an hour. Come
along. Ahoy!"

Still no answer; and in spite of his companion's suggestions and strange
doubts Dick kept on hunting about in the darkness among the patches of
alders and the heath that here grew freely. For, save in places, the
ground was sandy and firm, and, dark as it was, they had no difficulty
in making out the watery spots by their faint gleam or the different
character of the growth.

They shouted in turns and together, listening, going in different
directions, and all to no purpose. Not a sound could they get in reply;
and at last, with a curious feeling of horror stealing over him,
compounded of equal parts of superstition and dread lest the person
whose cry they had heard had sunk in the mire of some hole, Dick
reluctantly gave way to Tom's suggestion that they should go back to the
boat.

"I knew it was something queer," whispered Tom. "If we had gone on, we
should have been led into some dangerous hole and lost."

"Don't believe it," said Dick, as they trudged slowly back, utterly
worn-out and hoarse with shouting.

"You're such a doubting fellow!" grumbled Tom. "If it had been anybody
in distress we should have found him."

"Perhaps," said Dick sadly. "It's so dark, though, that we might