the one the hunchback had entered the night before.

  Barakoff was located at last! But how was he to be captured? Theproblem was not so easy.

  It was vital that, if possible, he should be taken alive. They knewwhat would follow the explosion at Finsbury Park, and there was a chanceat least that if Barakoff were captured the secret of the disease, andpossibly the antidote, might be wrung from him. If they could succeedin that hundreds of lives would be saved.

  Together the three worked out a careful plan for the _coup_ theyintended to bring off next morning.

  Very early a dozen street arabs were playing innocently close to the twoentrances of the mysterious building. They were chosen specimens ofYvette's band of ragamuffin detectives, and she knew that if Barakofftried to escape he would have no chance of eluding their keen eyes. Allthe approaches were blocked by detectives, but Yvette insisted that noneshould approach the house itself. It was essential to the success oftheir plan that Barakoff's suspicions should not be aroused.

  From the roof of a big building half a mile away, Dick made a carefulexamination of what he was now convinced was Barakoff's hiding-place.But he could see little. The roof was flat, but it was surrounded by aparapet practically breast high. There was obviously plenty of room toconceal a small aeroplane, but Dick could see nothing.

  Dick and Buckhurst together saw the proprietor of the building fromwhich Dick had made his observations. He readily consented to Dick'splan, and towards evening placed a trusty commissionaire at the foot ofthe flight of steps leading to the roof with instructions that no onewas to pass on any account whatever. Soon after dark the Mohawk droppedsilently on to the flat roof. They were ready now to catch their bird!

  In the morning Yvette, under the pretence of wishing to buy some oldfurniture, entered the shop. So far as she could see there was nothingsuspicious. There was a manager, evidently a Russian, and twoassistants.

  Asking for a Jacobean chest which she did not see in the shop, Yvettewas at length invited to the upper floors. These she found to be fullof furniture.

  Climbing the stairs to the third floor, accompanied by the manager,Yvette found herself in a large room divided in the centre by a wall,and with a door in the middle. Opening this door the manager bowed toher to precede him, and Yvette, quite unsuspectingly, obeyed. Nextsecond the door crashed to, and she heard a key turn in the lock. Shewas trapped!

  Before she could recover from her astonishment there was a rush of feetbehind her, and she found herself seized in a grip which, as she at oncerecognised, it was far beyond her strength to shake off. She struggledfrantically, but in vain. She was hopelessly overpowered and swiftlybound, and laid, gagged and helpless, on a sofa in the corner of theroom. Then for the first time she caught sight of her captor. Sherecognised him at once. It was Barakoff himself! _Worse still, he knewher_!

  The man was mad with rage, his face convulsed and his eyes blazing withfury.

  "So, Mademoiselle Pasquet! We meet at last!" he snarled, stooping overher until his face was within a foot of her own and she could feel hishot breath upon her cheek. "But it is for the first--and last time!"

  Accustomed as she was to danger in many forms, Yvette could not repressa shudder. In the power of a ruffian like Barakoff! She knew, ofcourse, that at any moment Jules might become suspicious of her longabsence and come in search of her. But how long would he be and whatmight happen in the meantime?

  Barakoff set swiftly to work and fixed inside the doors heavy barswhich, as Yvette realised with a sinking heart, would effectually shutout anyone trying to gain admittance, until either the door was reducedto splinters or a hole was knocked in the wall. Then he picked her upwithout an effort and carried her into the adjoining room. This, toYvette's intense surprise, was elaborately fitted up as a chemicallaboratory, with all kinds of strange instruments and apparatus. It wasevident that it had long been used for this purpose.

  With an evil sneer Barakoff took from a cupboard what Yvette had nodifficulty in recognising as one of the poison bombs! This he placed ona table and attached to it a short length of fuse. Then he began tobusy himself with what seemed to be preparations for leaving, packing afew articles of clothing in a small bag and laying it down with a heavycoat beside it.

  "When night comes, I go," he said. "But you--you will remain. But Ishall leave you in good company, mademoiselle," and he pointed to thedeadly bomb. "You will not feel dull. And after I am gone you willdie--very slowly--of the twisted arms."

  For a few minutes the miscreant sat silent, smoking a cigarette andregarding Yvette with a look of triumph she found even harder to bearthan the consciousness of her terrible danger.

  Jules, on watch below, had at length become uneasy. He entered the shopand asked one of the assistants if the lady was still there.

  "Yes," replied the fellow readily, "she is upstairs with the managerlooking at some furniture."

  Jules, his hand on his pistol in his pocket, and feeling strangelyuneasy, started up the stairs. There was no one in the building. Whatcould have become of Yvette and the manager?

  On the third floor he noticed the door through which Yvette had gone.He seized the handle and tried to open it. But the door was locked andthere was no key.

  Not daring to raise an alarm for fear of the consequences to Yvette,Jules hastened down the stairs, and signalled to one of the ScotlandYard men. In a low voice Jules told him what had happened.

  "We must be ready to break down that door at once," he said.

  With swift efficiency help was summoned, including a couple of men ofthe salvage corps, armed with powerful axes which would make short workof any ordinary door.

  While the shop assistants were kept under surveillance, Jules and hishelpers mounted to the third floor. They tried the door, and knocked.There was no reply, but inside they heard the hasty scurry of feet.

  "Break it down," said Inspector Buckhurst, who had been one of the firstto arrive.

  The salvage men sprang forward, and one on each side of the door began afurious attack with their axes.

  Instantly a shot rang out. Splinters flew in showers, but the door,heavily barred and plated with iron, for a time defied all theirefforts. At last it gave way, and headed by Jules the police partyrushed in.

  Their first discovery was Yvette, lying unconscious and bleedingprofusely from a wound in the shoulder. Barakoff had fired at her as hehurried from the room when the thunderous attack on the door began. Butin his blind haste his aim had been bad, even at such short range, andshe escaped with comparatively slight injury.

  But where was Barakoff?

  Rushing out on to the flat roof Jules looked hurriedly round. To thesouthward a queer-looking aeroplane was just vanishing into the thinmist. But behind it, going "all out," sped the Mohawk in furiouspursuit. Dick Manton was taking a hand in the game of which he was amaster! There could be but one end to that, Jules thought, with a sighof relief as he turned to look after Yvette.

  She was recovering consciousness and they were just about to carry herout, when one of the policemen with a loud cry dashed to the table. Hehad caught sight of a thin thread of smoke rising from the fuse of thebomb!

  Luckily he was an old bombing instructor and knew what to do. A momentlater the fuse was cut and the bomb's detonator removed. It washarmless now. Half a minute later it would have exploded.

  Watching keenly from his roof Dick Manton had seen Barakoff's aeroplanerise swiftly and silently into the air. He had some slight trouble instarting the Mohawk, and the Russian was a mile away before theEnglishman had started in pursuit.

  Crouched in the driving seat of the Mohawk, Dick kept his eyes glued onthe machine in front. He soon realised, to his dismay, that the Russianmachine was much the faster and was leaving him behind. By the timethey had gone ten miles and were out over the open country, he couldonly just discern the fugitive as a mere speck in the distance, and herealised with a sinking heart that a fleck of mist would enable Ba
rakoffto escape.

  Suddenly he discovered that the Russian machine had descended very low.A moment later it appeared to rise vertically, going up to a greatheight.

  Instantly Dick followed and to his surprise found himself gainingrapidly. Then the Russian seemed to slip ahead again.

  Several times this was repeated, and Dick at length divined the reason.The Russian could not run his elevating and driving propellerssimultaneously. He travelled in a series of swoops, coming down veryslowly as the machine drove forward, and then being compelled to stopthe driving propellers while he gained the necessary height to continuehis flight. No doubt this was explained by the fact that the planeswere too small to keep the machine up without the elevating propellers.

  Dick saw that he held a big advantage. The Mohawk, though slightlyslower, could rise and go forward at the same time under the influenceof both propellers.

  As they sped over Kent, Dick began to realise with joy that he wasgaining. Slowly the