"Oh," observed the detective to himself, "it seems she's playing a deeper game than I thought."

"Do you know whether she has left Paris?" he asked of the clerk, to whom he was known as a police agent.

"I really don't. The maid called the cab and I did not notice the number."

"You didn't hear the cabman receive any orders?" The clerk shook his head.

"Ah, that is unfortunate," observed the detective, perplexed. "Would not any one be likely to know where they went?"

"No; I was the only person in the courtyard when the cab drove out."

The detective, with an expression of disappointment replaced the paper in the envelope, and, announcing his intention of keeping it, placed it in his pocket. Then he left the hotel, and sauntered along to a small cafe in the Rue Auber, nearly opposite the Eden Theatre. That he had displayed a serious error of judgment in not acting with greater prompt.i.tude it was impossible to deny, and he was endeavouring to fix upon some plan whereby he could trace the woman who had left her husband so mysteriously and in such suspicious circ.u.mstances. Had he been wise, he told himself, he would have had an interview with Madame Trethowen as soon as her husband had been safely lodged inside the Prefecture. Now, however, he was baffled.

Evidently she feared a visit from the police, he argued, otherwise she would not have decamped, leaving only a piece of plain paper for her husband. Besides, the fact that she had left such a note was sufficient evidence to the detective that she was a clever woman, and, moreover, that she was desirous of hiding herself.

He remained at the cafe only long enough to swallow a gla.s.s of absinthe, then, hailing a cab, drove back to the Prefecture and consulted his chief.

From the central office inquiries were at once inst.i.tuted, and within an hour it was ascertained that madame and her maid had driven from the hotel to the Gare du Nord, and left by the Brussels express, which started at 12:40. They had not booked to Brussels, but to Masnuy St.

Pierre, a small Belgian town midway between Mons and Braine-le-Comte.

Monsieur Chemerault drove at once to the terminus, with the object of stopping them by telegraph before they left France. Almost breathless he alighted from his cab, and rushed upon the platform.

In a few moments he found the time-table of which he was in search.

Running his finger down it, he saw that the train was timed to arrive at Quevy at half-past four, and at Mons at 5:02.

He glanced up at the large dock. It was a quarter past five.

"_Diable_! She's beaten us!" he cried with chagrin. "She's crossed the frontier and escaped!" At that moment one of his colleagues joined him.

"We're too late," said Chemerault disappointedly. "She's got clear away. Somehow, I have a conviction that there is more in this case than we imagine. We must keep our eyes open, for if we arrest her, and she turns out to be the woman I believe she is, we shall find we have made a very important capture."

"Who is she?" asked his companion.

"Well, her name is Valerie--not an uncommon one, I admit; but if I was certain the surname she was once known by was Duvauchel, I would apply for her apprehension in Belgium, and extradition."

"Duvauchel! Why, that was in connection with the affair near St.

Lazare, wasn't it--that celebrated case of yours?"

"Yes; I was unable to find a key to the mystery at the time, and now, after several years, the matter has come again into my hands quite unexpectedly," replied the detective. "To-morrow I shall recommence my inquiries, for the crime has always been particularly puzzling to me, and I should like nothing better than to be able to clear it up satisfactorily."

His companion expressed a hope that he would succeed, as both left the station, and directed their steps towards the Quai de l'Horloge.

CHAPTER TWENTY FIVE.

SHEKELS OF JUDAS.

Midnight in Brussels. Six months had pa.s.sed since Valerie's hurried exit from Paris had baffled the most expert member of the Paris detective force.

The streets were quiet, almost deserted; the trees in the boulevards were stirred slightly by the soft wind, and the long lines of gas lamps flickered and cast an uncertain light as Pierre Rouillier, in evening dress, and with an Inverness cape about his shoulders, emerged from the Rue de Pepin, crossed the boulevard, and turned into the Chausee de Wavre. Whistling softly to himself, he continued his walk down the long, straight thoroughfare until within a few yards of the Rue Wiertz, where, before a large and rather gloomy-looking house, he halted. He gave two vigorous tugs at the bell, and Nanette opened the door.

"Ah!" the mud exclaimed, with familiarity, "it's a good thing you've come. Mademoiselle has been so anxious about you. Most of them are in a fine state."

"What! have they had supper, then?"

"Yes; and there are several fresh people--swells."

"Who are they?"

"You'll see."

"Who's there, Nanette?" asked a shrill, musical voice.

"M'sieur Rouillier, mademoiselle," replied the girl.

"Ah, Pierre!" said the voice; then it could be heard repeating in another direction: "Our young friend, Pierre, has arrived."

Immediately there was a chorus of approbation, and some one commenced singing the first verse of the _chansonette_, "Pierre, my long-lost love," as that distinguished personage walked into the room. Valerie was standing at the door, and whispered to him--

"There are some rich men here to-night. We can make a big _coup_ if we are careful."

Then, turning to her guests, she exclaimed--

"Cease your chatter, please, just for one moment. Ladies and gentlemen, it is my pleasure to introduce to you--"

This was greeted with discordant cries--

"Enough! Everybody knows Pierre."

"Ladies, do please listen to me," implored Valerie. Continuing, Valerie again endeavoured to make herself heard.

"Gentlemen, I--"

At that moment somebody commenced to strum a waltz upon the piano, and, as if by magic, the twenty persons in the room rose to their feet and commenced to whirl madly round, while Valerie and Pierre stood at the door whispering and regarding the scene of Baccha.n.a.lian revelry with perfect satisfaction.

She liked to see her guests enjoy themselves.

"I want a few moments' private conversation with you," Pierre said, after they had been standing silent for a minute or two.

She acquiesced at once, and led the way to a small anteroom behind the drawing-room. It was furnished gaudily and cheaply, but quite in keeping with the rest of the house.

As he closed, the door, Pierre said--

"I've some good news."

"What is it?" she asked.

"Victor has fallen into the trap."

"Arrested?"