was necessarily ignorant, and that it must be related to some affairwhich was pending in England. The more he thought about it the moreuneasy he grew. He had the premonition which so often comes to the helpof the detective, and at length, though he was almost ashamed of actingon such slender grounds, he decided to consult his chief. An hour laterhe was on his way to Paris, leaving the affair of the bank swindlers inthe hands of a capable subordinate.
Arriving in Paris he drove straight to Regnier's private apartment, justoff the Place de la Concorde.
"Why, Manton, what brings you here?" asked Regnier in surprise. "Haveyou finished at Barcelona already?"
For answer Dick laid the deciphered cryptogram before the Chief.
"What do you make of that?" he asked abruptly.
Regnier read the slip of paper with knitted brows.
"Queer," he commented. "Why should it be published in the `Diario'? Ithink it means mischief. Do you know Chalkley?"
Dick shook his head.
"No," he replied, "but it sounds like an English name. And yet I have afeeling that I must have heard it somewhere. It sounds familiar, but Icannot place it. In the meantime I will run home and see if the Englishpapers will tell me anything."
Dick found Jules and Yvette eager for news; he had telegraphed them thathe was returning. Dick, Jules, and Yvette had become the mostformidable combination in the French Secret Service. They alwaysinsisted on working together, they would accept no assistance exceptthat which they chose themselves, and they would work only under thedirection of Regnier, who was astute enough to realise their abilities.Yvette had been prevented by a slight illness from accompanying Dick toBarcelona, and both she and Jules, who had stayed with her, hatedinaction. There had been a slump in international crime of the kind inwhich they specialised, and they were suffering from _ennui_. Anythingwhich promised excitement and adventure was welcome.
They listened eagerly while Dick told his story.
"And now," said Dick, half ruefully, as he concluded, "I don't knowwhether we are on the track of something or whether I have been anidiot."
Yvette's eyes were dancing with merriment.
"Well, Dick," she said, "you are certainly a pretty Englishman not toknow one of the most famous places in your own country. Don't youreally know Chalkley?"
"No," replied Dick in bewilderment. "What do you know about it?"
For answer Yvette rummaged among a pile of newspapers and produced acopy of the "Times" dated a week before.
"There?" she said. "Read that."
"That" was a closely printed column which Dick proceeded to scan withattention. It was an article describing the wonderful deposits ofpitchblende, the ore from which radium is extracted, which had beendiscovered in the Ural region in the neighbourhood of Zlatoust. AnEnglish combine had secured the monopoly of the working for fifteenyears, and already a supply of radium valued at one hundred and fiftythousand pounds had been brought home by the famous Professor Fortescuefor the use of British chemists and medical men.
The discovery and acquisition of the monopoly by British interests, thearticle pointed out, had put England far ahead in the field of radiumresearch, for she had now a big supply of the precious commodity at herdisposal, while other nations were struggling along with the tinyquantities obtained from other and far less rich deposits. And, as wasfully explained, it was not in medicine alone that the radium would bevaluable; there was hardly a department of commerce, to say nothing ofthe arts of warfare, in which radium was not playing a considerable andconstantly increasing part. So many new discoveries were being made bythe band of experts, of whom Professor Fortescue was the acknowledgedhead, that it was beginning to be realised that radium in the future waslikely to be as valuable as coal and oil had been in the past.
But--and here was the fact of most significance to Dick--the radium wasat Chalkley, Professor Fortescue's home in the wilds of the Durhammoors. He had taken it there on his return from Zlatoust for use insome critical experiments he had in hand before it was sent on to theyoung but growing school of Medicine at Durham University.
They had at least approached the heart of the mystery! It was evidentthat some band of international desperadoes had designs on the preciousradium. In spite of their enormous value, the two tubes containing thesalt could easily be carried in a man's pocket, and in Germany therewould be a ready market for it among the great chemical firms, whosebusiness consciences were sufficiently elastic to permit them to pay abig price and ask no awkward questions.
Dick was reading the report carefully, when he suddenly gave a startledexclamation.
"Why, look here," he said, "the radium is only to be kept at Chalkleytill the twenty-ninth. That explains the twenty-nine in theadvertisement. And to-day is the twenty-seventh. If anything is tohappen it must be at once or they will be too late. I must ring upRegnier." Regnier was with them in half an hour. He was filled withexcitement when he learned the facts which Yvette had discovered.
"That," he said, "puts an entirely new complexion on the affair. Therecan now be very little doubt about the matter. Clearly `lead' meansradium, and I think we can interpret `bull market' as an intimation thatit is a big prize. They are evidently well informed, whoever they are.We must tell London at once."
But before anything could be done a messenger for Regnier arrived posthaste from the bureau of the Secret Service in the Quai d'Orsay withstrange news.
A big aeroplane, flying at a tremendous speed, had crossed theFranco-Spanish frontier near Bagneres de Luchon having apparently comeright across the Pyrenees. It had ignored all the signals of the Frenchfrontier guards, whose aeroplanes had, in consequence, gone up inpursuit. Only one of them was fast enough to approach the stranger, anda fight had followed in which the French machine was crippled and forcedto descend. Thereupon the strange machine had proceeded, flying in thedirection of Bordeaux. Telephone messages had brought warning of itsapproach, and several attempts had been made to stop it, but withoutsuccess. It had been reported, chased by French aeroplanes overBordeaux, Nantes, and St Malo, and at the latter place, just as duskwas falling, it had left the French coast and laid a course apparentlyfor England. No further news of it had been received.
Regnier looked grave.
"Of course," he said, "we have absolutely no reason to couple thismachine with the advertisement in the `Diario,' but I confess I amuneasy. There is at Chalkley radium worth a fortune, easily carried ifanyone can get hold of it, and readily convertible into cash. Whatbetter device could be employed than a fast aeroplane which could get toDurham and away before anyone could hope to stop it? In any case, I amgoing to telephone Scotland Yard at once."
Half an hour later he was in communication with Inspector Cummings, thesenior officer on duty at the Yard. To him he explained his suspicions,half afraid, with the Frenchman's dread of ridicule, that the otherwould laugh at his story as an old woman's tale.
But Inspector Cummings was too experienced to be neglectful or scepticalof anything which could disturb Regnier, whom he well knew to be one ofthe most astute and level-headed of men. He took the matter seriouslyenough.
"We have heard nothing yet," he said. "But I will 'phone Durham at onceand let you know in the course of an hour."
They waited anxiously for the reply. It came at last.
"Cummings speaking," said the voice on the 'phone. "I have spoken toDurham. They have heard nothing there, but they are unable to obtainany reply from Professor Fortescue. The telephone exchange reports hisline out of order.
"But here is a queer thing. A big aeroplane, evidently a foreigner, wasreported this morning to have been seen over the Midlands flying north.There was a lot of mist about, and we have not been able to trace themachine yet. But it was certainly not one of ours."
"Well," said Regnier, "will you keep me posted? I fancy you will havemore news before long. In any case, you will have Durham warned?"
"I have warned them myself," replied Cummings, "an
d they are sending acouple of men out in a motor to make inquiries. You know Chalkley isabout twenty-five miles from Durham and quite in the wilds. ProfessorFortescue was, a couple of years ago, carrying out some experiments inwhich it was absolutely necessary he should be away from anything liketraffic vibrations, and he chose this place for the purpose because itwas remote from any railway or heavy traffic. He has stayed there eversince; he said it suited him to be `out of the world,' as he called it."
Three hours later came still more startling news.
The police officers who had gone from Durham to Chalkley had found thattwo armed men had made a raid on Professor Fortescue's house. They hadgagged the servants, who were found lying bound and helpless, and theProfessor