“Wait until we’ve had our interview with M. Dudouis. For we shall see M. Dudouis at the prefecture, shall we not?”

“Yes, he’ll be there at three o’clock.”

“Well, you’ll be convinced, Mr. Inspector! I tell you here and now that you will be convinced.”

Rénine was chuckling like a man who feels certain of the course of events. Hortense, who was standing near him and was able to speak to him without being heard by the others, asked, in a low voice:

“You’ve got him, haven’t you?”

He nodded his head in assent:

“Got him? I should think I have! All the same, I’m no farther forward than I was at the beginning.”

“But this is awful! And your proofs?”

“Not the shadow of a proof … I was hoping to trip him up. But he’s kept his feet, the rascal!”

“Still, you’re certain it’s he?”

“It can’t be anyone else. I had an intuition at the very outset, and I’ve not taken my eyes off him since. I have seen his anxiety increasing as my investigations seemed to centre on him and concern him more closely. Now I know.”

“And he’s in love with Madame Aubrieux?”

“In logic, he’s bound to be. But so far we have only hypothetical suppositions, or rather certainties which are personal to myself. We shall never intercept the guillotine with those. Ah, if we could only find the banknotes! Given the banknotes, M. Dudouis would act. Without them, he will laugh in my face.”

“What then?” murmured Hortense, in anguished accents.

He did not reply. He walked up and down the room, assuming an air of gaiety and rubbing his hands. All was going so well! It was really a treat to take up a case which, so to speak, worked itself out automatically.

“Suppose we went on to the prefecture, M. Morisseau? The chief must be there by now. And, having gone so far, we may as well finish. Will M. Dutreuil come with us?”

“Why not?” said Dutreuil, arrogantly.

But, just as Rénine was opening the door, there was a noise in the passage and the manager ran up, waving his arms:

“Is M. Dutreuil still here? … M. Dutreuil, your flat is on fire! … A man outside told us. He saw it from the square.”

The young man’s eyes lit up. For perhaps half a second his mouth was twisted by a smile, which Rénine noticed:

“Oh, you ruffian!” he cried. “You’ve given yourself away, my beauty! It was you who set fire to the place upstairs, and now the notes are burning.”

He blocked his exit.

“Let me pass,” shouted Dutreuil. “There’s a fire and no one can get in, because no one else has a key. Here it is. Let me pass, damn it!”

Rénine snatched the key from his hand and, holding him by the collar of his coat:

“Don’t you move, my fine fellow! The game’s up! You precious blackguard! M. Morisseau, will you give orders to the sergeant not to let him out of his sight and to blow out his brains if he tries to get away? Sergeant, we rely on you! Put a bullet into him, if necessary! …”

He hurried up the stairs, followed by Hortense and the chief inspector, who was protesting rather peevishly:

“But, I say, look here, it wasn’t he who set the place on fire! How do you make out that he set it on fire, seeing that he never left us?”

“Why, he set it on fire beforehand, to be sure!”

“How? I ask you, how?”

“How do I know? But a fire doesn’t break out like that, for no reason at all, at the very moment when a man wants to burn compromising papers.”

They heard a commotion upstairs.