"They really believe you're out of England. You're quite sure of that?" questioned Brockman, in his thick, guttural voice.

"As sure of it as you're standing there," answered Zuker. "The search for me went on actively for a fortnight, and then dropped. How should they suspect a hiding-place like this? How should they suspect that when the hounds were in full chase of the fox, he had a hole to retreat to where they could never follow?"

"Ha! ha!" chuckled Brockman; "we ought to call it the Fox-Hole. I only wish we had the youngster in it who slipped through my fingers that night on the road to Redmead."

"Do you really?" said Paul to himself. "Well, the youngster's obliged you, and yet you don't seem to be grateful to him."

"Zut! zut! Don't worry about him. He's only a cipher—a pawn in the great game we have in hand. If we win, it'll be for a prize worth winning—fame and fortune," went on Zuker, as he strode to and fro with rapid strides. "Yes, fame and fortune, and we shall have dealt a staggering blow at a country that we hate. The risk is great, but the stakes are greater still, and each day makes our position surer."

"Surer? Do you think so? Sometimes it seems to me, master, that we're standing on the very edge of a deep precipice, and that one day we shall make a false step, and then——"

Brockman did not finish the sentence, but gave a significant shrug of the shoulders which was much more eloquent than words.

"Das ist recht—that is right; I have never hidden from you the danger. It is true that one false step might spoil all my plans, but that only makes the game more worth the winning. And listen, Brockman, we must not make that false step. We made one on that night we let the boy get through with the cipher to Redmead. We must not make another."

Paul's ears tingled as he listened. Notwithstanding the peril in which he stood, his heart beat with joy. The words of Mr. Moncrief came back to him: "You have not only done a great service for me and my brother, Paul, but for your country." He had almost forgotten those words in the whirl of events that had since happened at Garside, but now they came flashing back, shining out vividly as a beacon in the darkness around him.

"No; we must not make another," answered Brockman, sending his fist vigorously into the palm of his hand to emphasize his words. There was silence between the two for a moment, then it was again broken by Zuker.

"Those ancestors of yours were dull dogs, Brockman, but there must have been some grit in them to have got up to Chatham. See, they got to this point." Paul could see that a chart was spread out upon the table, and that Zuker was pointing with his finger to a place on it. "Here is the River Medway, which, as you know, can be reached through this tunnel."

The river through that tunnel! Was he awake or dreaming? Paul could scarcely believe the evidence of his ears. His heart thumped so loudly against his ribs that he feared the conspirators might hear him.

"A chain had been drawn across the river, for all England was in a state of alarm at the approach of the Dutchmen," went on Zuker. "Fortifications had been added to Sheerness and Upnor Castle just here."

Brockman bent over the chart and followed the finger of Zuker.

"Just there. And the chain—what happened to the chain?"

"Sheerness was first taken, and then, taking advantage of a spring tide and an easterly wind, the Dutch broke the chain."

"Broke it? But wasn't it fortified?"

"It was guarded by three ships, but the Dutch took them. They played havoc with several other vessels, and advanced with six men-o'-war and five fireships as far as Upnor Castle, where they burned three more. That was good, wasn't it?"

"Splendid! Real pluck! Dull dogs and slow, as you say, but real grit. I'm proud of my Dutch fore-fathers."

It was clear that Brockman, if not himself a Dutchman, was of Dutch descent.

"The Dutch," continued Zuker, "then fell down the Medway—see, in this direction." His finger again went to work over the chart. "They sailed next to Portsmouth; they assaulted Harwich, and then sailed again up the Thames as far as Tilbury—this point here—where they were repulsed. What has been done once can be done again. Why not?"

Zuker, in his excitement, strode over in the direction of the curtain. Paul drew back and waited. Had he seen the curtain move? Did he suspect there was a listener behind? For a moment Paul scarcely breathed. Then he heard Zuker pacing back to the table, and breathed freely again.

"You forget the difference in the times," answered Brockman. "Then there were no ironclads."

"I'm forgetting nothing. Ironclads are useless without the brains behind them. Battles nowadays are won not so much on the battlefield as by the Intelligence Department—the Secret Service"—his voice went almost to a whisper—"the service to which you and I belong."

A cold feeling of horror and repulsion stole over Paul as he listened. He felt as he might have felt in listening to the rattle of a deadly snake. These men were in the Secret Service of another country—spies, collecting material for the enemy—material which might be used at any time with deadly effect against England, dear old England! And as he looked, a mist seemed to rise before him, and suddenly out of the mist he saw a strange picture—the cabin of a ship, a man bending over a dispatch-box, and rapidly turning over the papers within. Then the door of the cabin opened. An officer, with a bronzed, noble face swiftly entered, and seized the spy at the dispatch-box. The spy threw himself at the officer's feet and pleaded for mercy. Paul saw it all as clearly as though it were on a screen before him. Looking at the spy's face, he knew it for Zuker. Looking at the officer's face, he knew it for his father's.

As the scene faded, he felt that he, too, must spring out on Zuker and denounce him. "Spy—traitor! You're the man who tried to betray my father! You are the man who would betray Britain!" By some impulse over which he had no control he tried to shriek out the words. His lips moved, but fortunately no sound came from them.

The next instant he was brought to his senses by the sound of footsteps—footsteps in the tunnel by which he had entered. Instantly he realized the position in which he stood. The new-comer, whoever he was, was probably a confederate of the two spies inside, and would be bound to pass into the cave through the curtain behind which he was hidden. Quick as thought he retreated a pace or two, well out of the light of the lamps, and drew himself close up to the wall.

Nearer and nearer came the footsteps. Presently Paul could just see the shadowy outline of a man's figure. Then he passed him, coming so close that his coat brushed against him. The figure paused. Paul held his breath, and for one brief instant thought that he had been discovered. The next, the curtain was lifted aside, and the new-comer passed inside the cave.

"Ah, Weevil! What news?" came the voice of Zuker.

Weevil! Paul crept again to the curtain, and peered through the side. It was the master, sure enough. He wore a cape, with the collar turned up and buttoned tight round the chin.

"Still the same," answered the master.

"No change?"

"No change to speak of. Sometimes he's a little better; then he goes back again, and is worse. Poor little chap! it makes my heart bleed to see him."

Then Paul knew they were speaking of Hibbert.

"Your heart! What of mine?" exclaimed the man fiercely. "You always speak as though you were the only one who cared for the boy. And a lot of good you've done for him. It was through you I had him trained as an English boy. His mother was English, said you. It was through you he went to Garside, because you could take greater care of him, said you. What care? Himmel, himmel! You let those imps of Satan torture him; through you he has been brought to the door of death."

"Cease, man—cease to torture me!" cried the master.

Paul listened in wonder, not unmixed with awe. He had heard that note of anguish in the master's voice before—on that night when he had seen him by Hibbert's bed; but the face, with the light of the lamp flickering on it, might have been hewn from the limestone. It was as stern and rigid as Fate itself.

"I have no wish to torture you; but it sickens me to hear you speak about that boy as though it were no concern of mine—as though you were the only one who cared for him. I tell you again, I was a fool to let him go to Garside."

No answer came for a few moments. It seemed as though Mr. Weevil were struggling with his feelings. When he at length spoke, his voice was calm again. It had resumed that calm, deliberate tone with which Paul was so familiar.

"I would like to speak to you for a few minutes alone, Israel."

Brockman took the hint, and retreating at the other entrance of the cave, left the two together.

"I wished to speak with you alone, because I have discovered one or two matters which will interest you. You were struck, you may remember, with the name of the boy who saved Tim's life?"

"Yes; what of it?"

"You thought that he might be the son of that Captain Percival who years ago saved your life at the risk of his own. I knew that the boy's father was dead, and on examination of the school-books, I found that he was a naval officer. I was not aware of the circumstances under which he met his death, however. I have since discovered that he was drowned at sea 'whilst trying to save the life of a spy'—pardon me the word, but so the record runs."

"Ach! Is it possible?" came hoarsely from Zuker's lips. "I had my suspicions when I first questioned him."

Paul pressed his ear closer to the side of the curtain. He was anxious not to lose a word of what was spoken, for he knew that he was "the boy" to whom the master was referring; that "Tim" was, of course, Hibbert.

"I have discovered, further, that it was this same boy—Paul Percival—who got through with that letter to Redmead."

"The same? Ach Himmel! I caught but a glimpse of him in the darkness that night."

"The hand of a Higher than man is in it. You cannot escape it. Be warned in time. Give up this scheme of yours; if not for your own sake, for the sake of your son."

"Give up the scheme—the scheme for which I have worked so long. The scheme which, day by day, brings me nearer to fame and fortune. You talk like a madman. It is more to me than life itself—more to me than the life of fifty sons!"

A cry of pain came from Mr. Weevil's lips.

"I know you well enough—you have no love for my scheme. Your heart is in what you call science, and in the boy. You wish to frighten me—frighten me from the work which every day draws nearer to success. Shall I tell you what for? So as to drive me back to the Fatherland that you may keep all to yourself, my boy—the boy of your dead sister. Ach! I see through your scheming!"

"Hush, man—hush! Is it to hear reproaches from your lips that I have risked so much—that I have involved myself in these schemes of yours which may mean my ruin?" Mr. Weevil's voice was stern, fearless; but as quickly turned to a softer key. "Let us not quarrel, Israel. Heaven forbid that we should quarrel over the boy whom we both love in our own peculiar way. Remember that his life is still in jeopardy."

They shook hands, and then Mr. Weevil turned towards the curtain behind which Paul was hidden.