beat a retreat in good order, and
followed Colonel Hofferman, who was talking to de Naarboveck.

"The work of the Second Bureau," declared that officer.

Juve heard no more--Monsieur Lepine confronted him. The chief
commissioner of police was plucking at his pointed beard with nervous
fingers.

Drawing Juve aside, he asked:

"Juve, what is Headquarters thinking about?"

"I do not know, Monsieur."

"What! There is a visitor here, unnoticed.... Are you also ignorant
of the fact that the Baron de Naarboveck receives a king here
to-night?"

"Oh, as to that, I know it--Frederick Christian II."

Monsieur Lepine was incensed at the detective's calm.

"You know it! You know it!" he grumbled, "and the administration knows
nothing about!... Well, since you know so much, what is he doing here
your king?"

"He comes to see me."

"Juve, you are mad!"

"No, Monsieur, But."...

Juve cut short the conversation, approached the king, and said a few
words to him in a low voice.

The chief commissioner of police was surprised beyond words when he
saw the king listening attentively to what Juve had to say, then nod
acquiescence, leave the ballroom and enter the gallery on to which
several rooms opened, including the library at the far end.

Juve glanced discreetly at his watch. He was startled. His expression
altered. It grew severe, determined. He glanced about him, discovered
de Naarboveck not far off, and went up to him.

"Monsieur de Naarboveck," he said: "shall we have a few minutes' talk?
Not here--somewhere else.... Should we say?"...

"In my library?" proposed de Naarboveck, who looked the detective up
and down--a measuring glance, cold, contemptuous. Their glances
crossed, hard, menacing.

"You are set on it, Monsieur?" De Naarboveck's tone was irony
incarnate.... "And what may I ask is your aim in forcing this
conversation, Monsieur?"

Juve's reply came, distinct, determined:

"Unmask Fantomas!"

"That shall be as you like," was the diplomat's reply.

In the library, unusually full of furniture, Juve and de Naarboveck
met for their duel of words and wits.

They were by themselves. Juve had made the Baron pass into the room
before him. He knew there was but one exit--the door. If in order to
get clear away, de Naarboveck meant to employ force or trickery, he
would first have to remove Juve from the door, before which he had
stationed himself.

Juve did not budge.

Certainly there was the window a