ike a flash of lightning."

"Oh, Dummy, I'll never call you a thick-head again," cried Mark
excitedly.

"Why not? May if you like: I don't mind."

"Then you think," cried the lad, who was trembling now with excitement,
"that we might get into Ergles through our mine?"

"Sure I do--all along them grotters and passages."

"And take the ruffians by surprise?"

"Ketch 'em asleep, Master Mark. They'd never think of our coming
behind, like."

Mark seized the boy by the shoulders, and shook him as hard as ever he
could.

"Why, you stupid old, ugly old, cleverest fellow that ever was! Why
didn't you think of this before?"

"Couldn't, Master Mark," cried the boy, grinning as if he were
determined to display every tooth in his head; "it never come till this
morning. Right, aren't I?"

"Right! You must be. But suppose we can't get all the way?"

"Water does. Sure to be plenty of room. See how there always was."

"Hurrah! Then we'll go at once."

"What, us two?"

"Of course!"

"We couldn't fight all that lot. Six to one!"

"No; we must go and tell my father at once."

"That's best way," said Dummy, jumping off the stone. "Come on," and
they started off at once for the tiny camp, discussing the possibility
of the men finding the way through.

"Suppose they got into the mine, and attacked the Black Tor while we're
away?"

"No fear o' that, Master Mark," said Dummy, with another of his nice
open smiles. "Not many folk as would go and do what we did."

"No, I suppose not," said Mark thoughtfully.

"I'm sort of used to it, Master Mark, from always being down the mine,
and always wanting to see where every hole went. No, I don't think any
o' them would care to go. Too big and clumsy. They'd never get there."

CHAPTER TWENTY NINE.

PLAYING MOLE.

Sir Edward met them as they ascended the slope, Mark having been taking
mental notes all the way of the trend of the hills and the valley,
seeing for certain that, in spite of its bulk and height, Ergles was a
good deal lower than the range along the valley of the Gleame.

Their narrative of adventure below was listened to in silence, and Sir
Edward grew moment by moment more interested till the whole was told.

"I don't think there is a doubt of it," he said. "We are quite three
hundred feet lower here, and in all probability it is the same
underground stream as we have at the Tor; but whether it will be
possible to get right through into th