“Be at the Hotel Metzen at eight forty-five,” said I.  “Come by the Court entrance—­you will be expected.”

Then they rode away, and I hastened to the King.

As good luck would have it, Frederick was in his cabinet and received me instantly.  He read the letters and looked at me inquiringly.

“It means a plain talk between them,” I explained; “and I propose to hear it.  I am, sure it would interest Your Majesty—­much happened yesterday.”  And I told him of the Vierle Masque.

Frederick frowned a bit—­thought longer—­then smiled.

“I don’t much fancy eaves-dropping; but, sometimes, the end justifies the means,” he said.  “I’ll join you.”

“There will be other witnesses, Sire,” I said—­and named them.

“I don’t like it,” he said.

“I can stop them,” I suggested.

He considered.  “No,” said he, “I understand why you want them.  I’ll come—­they will be discreet.  And the Princess would wish it so.  I’ll bring her, myself.”

Then I rode to the Metzen.  Bernheim had preceded me and, with the manager of the Hotel, awaited me at a side door.  The corridor was dimly lighted but I drew my cape well over my face and, is a moment, we were in a small reception room.

“Monsieur Gerst,” said I to the manager, “I need your assistance.”

Gerst bowed very low.

“Your Royal Highness has but to command,” he said.

I was quite sure of that, however.  An Archduke of Valeria would have been quite enough, but the Governor of Dornlitz was beyond refusal.  I could have closed his Hotel by a word, and there would have been no appeal.

“Thank you, monsieur,” I said.  “You have as a guest, a certain Madame Armand Dalberg.”

“A guest by Your Highness’s express permission, you will remember,” he said.

“Very true,” said I.  “Now, this Madame Dalberg expects a visitor to-night at nine o’clock.”

He gave me a quick glance.

“You know him?” I asked.

“No, Your Highness.  I only know madame gave orders to admit no one to-night except a gentleman who would come at nine.”

I nodded.  “It’s the same,” said I.  “And what I want, is to hear all that occurs between Madame Dalberg and this visitor.”

Gerst smiled.  “That will be easily arranged, Your Highness—­the place is already provided.”

“The concealed Gallery?” asked Bernheim, quickly?

“Yes, Colonel.”  Then, to me, he explained:  “Madame’s reception room was once a part of a small, state dining-room.  Back of the end wall runs a gallery where guests sat to listen to the speeches.  It is there, now—­and the tapestries, with which the walls are hung, completely hide it.”

“It can be reached from the floor above?” I asked.

“Yes, Your Highness; a narrow stairway admits to it.”

“Can we enter without being overheard by those in the room below?”