All this Cuthbert saw and heard, as he stood in the shadow at the top of the stairs consumed by a burning curiosity.  Something had occurred of such overwhelming interest as to obliterate even from Kay’s mind for the moment the errand on which he had come, and his presence in the house at this moment awoke no question amongst the men assembled there, who were plainly otherwise engrossed.  All vanished again down the stairs, and Cuthbert stole after them with cautious footfalls, too eager to discover what could be so moving them to consider what he was doing.

It was easy to track, by their voices and the light they carried, the men who had preceded him.  The long flight of stairs terminated in a long stone passage, deadly cold; and this led in turn to a great cellar, at the far end of which a group of seven men was assembled.  They appeared to be standing round the entrance to a small tunnel, and this tunnel they had plainly been making themselves; for a number of tools for boring and picking lay about, and the faces, hands, and clothes of the assembled party plainly indicated the nature of their toil, albeit from their speech and bearing it was plain that all were gentlemen.

Robert Catesby was sprinkling the walls of this tunnel with some water, using words of supplication and exorcism, and his companions stood bare headed around him.  A great hush fell upon all as this ceremony ceased, and all seemed to listen intently.

“There is no sound; the devil hath taken flight.  I knew how it would be!” spoke the tall dark man exultantly.  “And now, comrades, to work again, for we have heard the last of our knell tonight.  No powers of darkness can stand before the charm of His Holiness’s power.”

With an air of relief and alacrity the gentlemen seized their tools, and again the hollow or ringing sounds commenced to sound in that dim place; but Kay had plucked Robert Catesby by the sleeve, and was whispering some words in his ear.

Catesby turned quickly round, made a few strides towards the staircase, and then catching sight of Cuthbert, stopped short, and seized Kay by the arm.

“Fool!” he cried, in a low, hissing tone, “what possessed you to bring him here?  We are undone!”

“Nay, but he knows; he is one of us.”

“He is not; it is a lie!  If he said so, he is a foul spy!”

And then striding up to Cuthbert with eyes that gleamed murderously, he looked into the youth’s face, and suddenly the fury died out of his own.

“Why, it is Cuthbert Trevlyn!  Good luck to you, good youth!  I had feared I know not what.  But thou art stanch and true; thou art a chip of the old block.  If it had to be some one, better thee than any other.  Boy, thou hast seen a sight tonight that must have awakened thy curiosity.  Swear to secrecy—­swear to reveal nothing—­and I will tell thee all.”

“Nay, tell me nothing,” answered Cuthbert firmly; “I love not mysteries.  I would fain forget all I have heard and seen.  Let me tell thee of Father Urban—­let me give thee his letters; but tell me naught in return.  I will not know—­I will not.”