course, and cross the marsh on the logs which you will find placed there for that purpose.  Beyond the marsh, or rather in the center of it, there is an island, which it is extremely difficult to reach by any other route than the one pointed out.  On it you will find Duffel, provided you are cautious and wary in your movements.  You will wonder how I am so familiarly acquainted with the operations of these bad men:  without fully satisfying your curiosity, let me say, that whatever I may have been, I am now desirous of handing over to justice one who is deeply guilty—­guilty of crimes of which even you, perhaps, have never dreamed of accusing him.  On this point I have only to say, you yourself came near losing your life in place of one of his victims.  I allude to the attack made upon you by two persons in the ‘dark passage,’ some weeks ago.  You will remember it!  I know all, though revealing but little; and as it will be known that treason is in the camp of the League of Thieves, I shall leave the country at once.  Go to the swamp as directed, and you will satisfy yourself of all that I have told you; but let me advise you to note strictly the directions I give you, and be extremely careful in your movements and choice of confidants.  Yours, for law and justice,

“EX LEAGUEIST.”

So soon as he finished reading this singular communication, the ’Squire asked the boy: 

“What sort of a man was he, that gave you the letter?”

“He was large, with dark eyes, and sun-burnt face.”

“You did not know him, then?”

“No, sir; he was a stranger.”

“That will do.”

The ’Squire was puzzled to know what to do.  The man might be acting in good faith, or he might be only leading him into a snare.  After mature deliberation, he came to the conclusion that his informant was not deceiving him, and resolved to act upon the suggestions of the unknown writer, be he friend or foe.

He accordingly set about making preparations for the adventures of the morning, without delay.  By midnight all his arrangements were completed, and he lay down to snatch a little rest before setting out on the expedition.  At three o’clock in the morning, the little company, numbering five in all, of whom Mr. Mandeville was one, set out for the swamp.

Bill and Dick had scarcely reached a safe distance from the cave, when a sound as of ten thousand thunderbolts rent the air, and the ground at the same time trembled as in a violent earthquake.  The horses plunged and snorted, and then stood still in mute fear.  The villains, who were looking in the direction of the cave, saw a column of fire, smoke, earth, and rocks heaved up in the air—­a huge mass like a mountain—­some portions to the height of several hundred feet, and then fall again with a heavy crash, making the earth vibrate beneath them.  They knew then that the cave was in ruins, and its place occupied by a shapeless mass of matter.