“How did you get in?” he demanded.

“Throttled your guard at the front door, took him down cellar and locked him in the coal-bin,” replied Mr. Grimm tersely.  “I am waiting for you to burn it.”

“And how did you escape from—­from the other place?”

Mr. Grimm shrugged his shoulders.

“The lamp is in front of you,” he said.

“And find your way here?” the prince pursued.

Again Mr. Grimm shrugged his shoulders.  For an instant longer the prince gazed straight into his inscrutable face, then turned accusing eyes on the masked figures about him.

“Is there a traitor?” he demanded suddenly.  His gaze settled on Miss Thorne and lingered there.

“I can relieve your mind on that point—­there is not,” Mr. Grimm assured him.  “Just a final word, your Highness, if you will permit me.  I have heard everything that has been said here for the last fifteen minutes.  The details of your percussion cap are interesting.  I shall lay them before my government and my government may take it upon itself to lay them before the British government.  You yourself said a few minutes ago that this compact was not possible before this cap was invented and perfected.  It isn’t possible the minute my government is warned against its use.  That will be my first duty.”

“You are giving some very excellent reasons, Mr. Grimm,” was the deliberate reply, “why you should not be permitted to leave this room alive.”

“Further,” Mr. Grimm resumed in the same tone, “I have been ordered to prevent the signing of that compact, at least in this country.  It seems that I am barely in time.  If it is signed—­and it will be useless now on your own statement unless you murder me—­every man who signs it will have to reckon with the highest power of this country.  Will you destroy it?  I don’t want to know what countries already stand committed by the signatures there.”

“I will not,” was the steady response.  And then, after a little:  “Mr. Grimm, the inventor of this little cap, insignificant as it seems, will receive millions for it.  Your silence would be worth—­just how much?”

Mr. Grimm’s face turned red, then white again.

“Which would you prefer?  An independence by virtue of a great fortune, or—­or the other thing?”

Suddenly Miss Thorne tore the mask from her face and came forward.  Her cheeks were scarlet, and anger flamed in the blue-gray eyes.

“Mr. Grimm has no price—­I happen to know that,” she declared hotly.  “Neither money nor a consideration for his own personal safety will make him turn traitor.”  She stared coldly into the prince’s eyes.  “And we are not assassins here,” she added.

“Miss Thorne has stated the matter fairly, I believe, your Highness,” and Mr. Grimm permitted his eyes to linger a moment on the flushed face of this woman who, in a way, was defending him.  “But there is only one thing to do, Miss Thorne.”  He was talking to her now.  “There is no middle course.  It is a problem that has only one possible answer—­the destruction of that document, and the departure of you, and you, your Highness, for Italy under my personal care all the way.  I imagined this matter had ended that day on the steamer; it will end here, now, to-night.”