The Villa Beni Hassan, a great red-and-white house of Moorish architecture, with three large domes, and many minarets, and long-arched windows of stained glass, I found standing high up, facing the azure sea, amid a wonderful tropical garden full of tall, feathery palms, dark oleanders, fiery pointsettias, and a perfect tangle of aloes, roses, giant geraniums and other brilliant flowers.

A high white wall hid it from the dusty highway, its position being between the road and the sea with spacious, well-kept grounds sloping away down to the golden beach. Truly it was a princely residence, one of the finest in the picturesque suburbs of Algiers. That afternoon beneath the blazing African sun, shining like burnished copper, all was still in the fiery heat, which, after the coolness of autumn in England, seemed overpowering.

At length the ricketty fiacre pulled up before great gates of ornamental iron-work, the tops of which were gilded, and on ringing, a gigantic Arab janitor in blue and gold livery appeared from the concierge's lodge, and salaamed.

In Arabic my companion explained that we wished to see the Comte, whereupon he opened the gates, and on foot we proceeded up the winding, well-kept drive, bordered by flowers, and shaded by palms of various species. On our left, across a sun-baked lawn, in the centre of which a big handsome fountain was playing, I caught sight of an aerial mast of iron lattice nearly a hundred feet high, and across from it to another similar mast were suspended four thin wires, kept apart by wooden crosses.

I held my breath. I was actually upon the domain of the most daring criminal known to the European police.

"There are the wires of the wireless station," the detective exclaimed. "But why, M'sieur, do you wish to see the Comte?" he asked with sudden curiosity.

"To ask him a plain question," was my brief and, I fear, rather snappish reply. "But tell me," I added, "have you ever seen his niece here visiting him?"

"Mademoiselle Sorel, M'sieur means. Yes, certainly. She has often been here—young, about nineteen—trÈs petite, and very pretty. She lives in Paris."

"Yes. When was she here last?"

"Ah! I have not seen her here for several months," replied the man in the shabby straw hat. "I saw the Comte only yesterday. I was in Mustapha Pasha when he went past in his grey automobile. He had with him the tall elderly Englishman who sometimes visits here, a M'sieur Vernon, I think, is his name."

"Vernon!" I exclaimed with quick satisfaction. "Is he here?"

"I believe so, M'sieur. He was here yesterday."

As he uttered the words we turned the corner, and the great white Moorish house, with the broad dark-red bands upon the walls, and dark-red decorations over the arched corridors, came into view.

Boldly we approached the front door, before which was a great arched portico lined with dark-blue tiles, delightfully cool after the sun without. Yet scarcely had we placed our feet upon the threshold when a tall servant, with face jet-black and three scars upon his cheeks, his tribal marks, stood before us with a look of inquiry, silently barring our further passage.

Beyond we saw a cool courtyard, where vine were trailing overhead, and water plashed pleasantly into a marble basin.

Again the detective explained that we wished to see the Comte d'Esneux, whereupon the silent servant, bowing, motioned us to enter a small elegantly furnished room on the left of the courtyard, and then disappeared, closing the door after him.

The room, panelled in cedar-wood, was Moorish in character, the light filtering in through long windows of stained glass. Around the vaulted ceiling was a symmetrical device in Arabesque in gold, red and blue, while about the place were soft Moorish divans and silken cushions, with rich rugs on the floor, and a heavy brass arabesque lamp suspended from the centre of the ornamented ceiling. The place was full of the subtlest perfume of burning pastilles, and, in a cabinet, I noted a collection of rare Arab gold and silver jewellery.

And this was the home of the motor-bandit of the Forest of Fontainebleau—the man who had shot dead the Paris jeweller, Benoy, with as little compunction as he killed a fly.

I strode around the room, bewildered by its Arabian Nights aspect. Truly Jules Jeanjean lived in a style befitting an Eastern Prince.

"Hush!" I exclaimed, and we both listened to a loud crackling. "That," I said, "is the sound of wireless telegraphy. A message is being sent out across the sea."

Jeanjean was evidently in a room in the vicinity.

Suddenly the noise ceased. The door-keeper, who had not asked our names, had evidently sent in the message that two strangers desired to see his master.

But it was only a pause, for in a few seconds the message was resumed. I could easily distinguish the long and short cracks of the spark across the gap, as the electric waves were sent into the ether over the Mediterranean to Europe.

I happen to know the Continental Morse code, for I had dabbled in wireless telegraphy two years before. So I stood with strained ears trying to decipher the tapped-out message. I heard that it was directed to some station the call-letters of which were "B. X." But the message was a mere jumble of letters and numerals of some pre-arranged code.

I listened attentively till I heard the rapid short sound followed by four long sounds, and another short one, which indicated the conclusion of the message.

Then we both waited breathlessly. Who was B. X., I wondered?

I felt myself upon the verge of a great and effective triumph. I would give Jeanjean into custody upon a charge of murder, and if Vernon were still there, he should also be captured at the point of the revolver.

Those seconds seemed hours.

In a whisper I urged my companion to hold himself in readiness for a great surprise, and to have his revolver handy—which he had.

I laughed within myself at the great surprise the pair would have.

The heavy atmosphere of the room where, from a big old bowl of brass with a pierced cover, ascended the blue smoke of perfume being burnt upon charcoal ashes, became almost unbearable. The pastilles as burnt by the Orientals is pleasing to the nostrils unless some foreign matter be mixed with them, or the smoke is not allowed to escape. In this case the round-headed stained glass windows were fully twelve feet from the ground, had wire-work in front of them, and apparently did not open. The designs of dark-blue, purple, red and yellow were very elegant, and they were probably very ancient windows brought from some fairy-like palace of the days before the occupation of Algeria by the French.

Again I gazed around the delightfully luxurious apartment, so essentially Moorish and artistic. Amid such surroundings had lived Lola—the girl who had fled from me and disappeared.

What would the world say when it became known that that magnificent house, almost indeed a palace, was the home of the man of a hundred crimes, the daring and unscrupulous criminal, Jules Jeanjean?

I was listening for a repetition of the wireless signals to B.X., but could distinguish nothing. Probably he was receiving their reply, in which case there would be no sounds except in the head-telephones.

"Mon Dieu!" gasped my companion, whose name he had told me was Fournier. "This atmosphere is becoming suffocating!"

I agreed, and tried to extinguish the fire within the brazier. Unfortunately I failed to open the lid, which was held down by some spring the catch of which I could not detect.

Indeed, the thin column of blue smoke grew darker and denser, as we watched. The room became full of a perfume which gradually changed to a curious odour which suffocated us.

We both coughed violently, and upon me grew the feeling that I was being asphyxiated. My throat became contracted, my eyes smarted, and I could only take short, quick gasps.

"Let's get out of this," I exclaimed, reaching to open the door.

But it was locked.

We were caught like rats in a trap.

In an instant we both realized that we were imprisoned, and began to bang violently upon the heavy doors of iron-bound and unpolished oak, shouting to be let out. The fool of an Arab had secured us there while he went to announce our visit to his master.

I took up a small ebony and pearl coffee-table inlaid with a verse from the Koran, and raising it frantically above my head, attacked the locked door. But when it struck the oak it flew into a dozen pieces. Fournier took up a small chair with equally futile result, and then in silence we exchanged glances.

Could it be, that on our approach to the house, we had been recognized by the owner and invited into that room which, with its rising fumes, was nothing less than an ingenious death-trap.

I remembered the sinister grin upon the villainous black face of the silent servant.

Again and again we attacked the door, for we knew that our lives depended upon our escape. We shouted, yelled and banged, but attracted no attention. We threw things at the windows, but they were protected by the wire-work.

Then a sudden thought occurred to me.

Swiftly I bent down and examined the large keyhole. The key had been taken and, it seemed to me, the heavy bolt of the lock had been shot into a deep socket in the framework of the door.

Without a word I motioned Fournier to stand back, and finding that the barrel of my revolver was, fortunately, small enough to insert into the keyhole, I pushed it in and pulled the trigger.

A loud explosion followed, and splinters of wood and iron flew in all directions. The bolt of the lock was blown away and the door forced open.

Next second, with revolvers in our hands, we stood facing two black faced servants, who drew back in alarm as we rushed from that lethal chamber.

Fournier, excited as a Frenchman naturally would be in such circumstances, raised his weapon and shouted in Arabic that he was a police-officer, and that all persons in that house were to consider themselves under arrest. Whereupon both men, Moors they were most probably, fell upon their knees begging for mercy.

My companion exchanged some quick words with them, and they entered into a conversation, while at the same moment, casting my eyes across the beautiful, blue-tiled, vaulted hall, I looked through an open door into the room which the Count d'Esneux used for his experiments in wireless.

At a glance I recognized, by the variety of the apparatus, the size of the great spiral transmitting helix, by the pattern of the loose-coupled tuning inductance, the big variable condensers, those strange-looking circular instruments of zinc vanes enclosed in a round glass, used for receiving, the electrolytic detector, and the big crystal detector, a gold point working over silicon, carborundum, galena, and copper pyrites—that the station must have a very wide range. The spark-gap was bigger than any I had ever before seen, while there was a long loading coil enabling any distant station using long wave-lengths to be picked up, as well as the latest type of potentiometer, used to regulate the voltage and current supplied to the detectors.

At a glance I took in the whole arrangement, placed as it was, upon a long table beneath a window of stained glass at the further end of that luxurious little Moorish chamber. Apparently no cost had been spared in its installation, and I fully believed that with it the notorious criminal could communicate with any station within a radius of, perhaps, two thousand miles.

Fournier had questioned the native servants rapidly, and received their replies, which were at first unsatisfactory. I saw by the fear in their faces that he had threatened them, when suddenly one of them excitedly made a statement.

"Diable!" cried the detective in French, turning to me. "The Count recognized us, and had us locked in that death-chamber while he and the Englishman, M'sieur Vernon, got away!"

"Escaped!" I gasped in dismay. "Then let us follow."

A quick word in Arabic, and the two servants, without further reluctance, dashed away along the big hall, through several luxuriously-furnished rooms full of soft divans, where the air was heavy with Eastern perfumes and the decorations were mostly in dark red and blue. Then across a small cool courtyard paved with polished marble, where another fountain plashed, and out to the sun-baked palm-grove which sloped from the front of the house away to the calm sapphire sea.

Excitedly the men pointed, as we stood upon the marble terrace, to a white speck far away along the broken coast of pale brown rocks, a speck fast receding around the next point, behind which was hidden the harbour of Algiers.

"By Gad!" I cried, gazing eagerly after it, "that's a motor-boat, and they are making for the town! We mustn't lose an instant or they will get away to some place of safety."

So together we dashed back to the road as fast as our legs could carry us, and drove with all possible speed back to the town, in order to reach the harbour before the fugitives could land.