moat. Isn't it strange that you didn't know of
this?"

"Strange!" cried Ben, taking the answer out of his young master's lips;
"why, I didn't know anything about it myself. I mean, where it was."

Roy was silent, for he was thinking of how easily the passage could have
been blocked, or a few men have held it against a host.

"Want to go any farther, sir?" asked the sergeant.

"Farther? Yes!" cried Roy, excitedly. "I want to go right to the end."

"Long way, sir, and it's all alike. It comes out in the old ruined
place at the top of that little hill."

"Yes, I suppose so," said Roy. "Lead on, please."

The sergeant went forward with the light, and Roy followed, whispering
to his companion as they went along.

"Oh, Ben, if we had only found it out!"

"Ay, sir. If we had only found it out; but it wanted a man like Master
Pawson."

"Why, Ben," cried Roy, who had a flash of inspiration; "he must have
found out about it in one of those old books from the library, one of
those which tell about the building of the castle."

"Why, o' course, sir!" growled Ben; "and you, with all those books to
look at when you liked, and not find it out yourself."

"And I know the very book," cried Roy, "and have looked at the pictures
in it scores of times. But, I remember now, I have not seen it since
that wretch has been here."

They had to increase their pace, for the sergeant was striding along
over the fairly level floor, which had doubtless been lately cleared,
for the lantern showed where portions of the arched roof had shaled off,
though much of it was in almost the same condition as when it was
laboriously chipped away with the mason's hammers, whose marks were
plainly enough to be seen.

"Seen one bit, we've seen all, Master Roy," said Ben at last in a
disgusted tone; "but it don't want a trained soldier to take a castle if
he's got a way in, made ready for him like this."

But they proceeded, and went right to the end, which was carefully
masked in the ruin of the old chapel. But some time before they reached
the other opening they were challenged, and Roy felt no surprise on
finding a strong body of horse bivouacked in the ancient ruin.

On the way back to the castle Roy gleaned a few facts from the sergeant,
which only, however, endorsed those already gathered,--to wit, that the
ex-secretary had been holding communications with the enemy for some
time before they came to terms, visiting the camp again a