answer.

  "But I beg--nay, I implore you to do so," she cried, holding out bothher hands to him.

  He shook his head slowly.

  "It is quite impossible. If danger really exists, then I must face it."

  For some moments she remained silent.

  "Have you seen Ghelardi lately?" she asked quite suddenly.

  Her question surprised. What, he wondered, could she know?

  "I saw him the day before yesterday," was his vague reply.

  "Has it not struck you that he is very ill-disposed towards you?" sheexclaimed.

  "Certainly. I have always known that--even while we were up the Nile,and he was passing as Jules Gigleux. He objected to our friendliness.Yet he never seemed to discover that you were acquainted with HenriPujalet. That was curious, was it not?"

  She smiled.

  "Perhaps because I was extremely careful not to betray it--eh?" Butnext second she glanced at the little diamond-studded watch upon herwrist, and rising quickly, declared that it was time for her to catchthe train back to Rome.

  "There is a luncheon to the Grand Duke of Oldenbourg to-day, and I shallbe in horrible disgrace if I'm absent," she explained. "But it will bebest for you to travel by the next train. It is injudicious for us tobe seen together, Mr Waldron, especially if we are watched--as Ibelieve we are."

  "Ghelardi's secret agents may lurk anywhere," he said, as they walkedtogether to the great gateway of the villa.

  "No, I do not fear them, I tell you," she said.

  "But just now you told me that he is ill-disposed towards me--a fact ofwhich I am well aware."

  "I tell you it is not Ghelardi that I fear, but certain persons who, fortheir own mysterious purposes, intend to make an attack upon you whenfitting opportunity offers."

  "Trust me to remain wary," replied Hubert with a smile, and then afterthey had stood together in the winter sunshine for several moments nearthe gate he lifted his hat, bowed low over her hand, and then stoodwatching until she, pulling her splendid furs about her shoulders, haddisappeared into the road which led down to the rural station.

  Ah! how he loved her! But he sighed and bit his lip.

  To Hubert, the object of Her Highness's warning seemed both mysteriousand obscure. Did she, for some hidden purpose of her own wish to getrid of him. If so, why?

  The story that an attempt might be made upon him he was inclined todiscredit, especially as she had refused to reveal the source of herinformation.

  He lunched at the little _albergo_ above the steps leading to thestation, and by half-past two found himself back again in Rome where, inhis rooms, he found Pucci, the brigadier of police, awaiting him.

  "I have a curious fact to report, signore," said the man when they werealone together with the door closed.

  "Well," asked Hubert, "what is it?"

  "That your movements are being closely watched by two well-knowncharacters--criminals."

  Waldron started, staring at the man, for had not Lola warned him thatvery morning.

  "Do you know them?"

  "Quite well. One is called `The Thrush' by his associates, and hasserved several long terms of imprisonment for theft. Indeed I arrestedhim three years ago for attacking a policeman in the Piazza Farnese andusing a knife. The other is Beppo Fiola, who has been sentenced severaltimes for burglary."

  "Professional thieves then?"

  "Two of the worst characters we have in Rome, signore."

  "I wonder what they want with me--eh?" asked Hubert, lighting acigarette, perfectly unperturbed.

  "They mean no good, signore," declared the man very gravely. "Perhapsthey intend to commit a burglary here?"

  "They are welcome. There's nothing here of any great value, and if theydo come they'll get a pretty warm reception," he laughed.

  "Ah, signore, it is a very serious matter," protested the detective."These two men would, if it suited them, take life without the slightesthesitation. In a case four months ago where a Russian diamond-dealerwas robbed of his wallet and his body found in the Tiber stabbed to theheart, the strongest suspicion attached to the two men in question,though we have not yet been able to bring home the crime to them."

  "But I haven't any diamonds or valuables," replied the diplomat.

  "No, but perhaps you, signore, may be in possession of some secret orother concerning them," the detective said. "Perhaps even they may beemployed by some enemy of yours to watch an opportunity and close yourlips."

  Hubert looked at the man in surprise without replying.

  "Yes, signore," Pucci added very gravely, "such a thing is not entirelyunknown in Rome, remember. Therefore I would urge you to exercise thegreatest caution; to beware of any trap, and always to carry arms. Itwould be best, I think, to report to the Questore, and arrest both menon suspicion."

  "No, Pucci," Hubert replied quickly. "No. Watch closely, but make nomove. Their arrest might upset all my present plans."

  CHAPTER TWENTY FOUR.

  ROOM NUMBER 164.

  Days, many anxious, fevered days, passed--bright winter days duringwhich Hubert was frantically active in his efforts to discover some clueto the mystery of the stolen plans of the frontier fortresses.

  Not a stone did he leave unturned in his quiet, patient endeavours, andaided by the faithful Pucci--to whom he still hesitated to reveal theexact object of his search--he kept constant watch upon the actions ofHis Excellency the Minister of War.

  Suspicions were very strong against the latter. He had discovered oneimportant point, namely, that within a week from the loss of thedocuments the sum of one hundred and sixty thousand lire was paid intothe General's account at the Banca Commerciale, and, further, that itappeared to have come from an unknown source.

  Agents employed by Pucci had also watched the two secretaries, Lambariniand Pironti, but against neither was there any suspicious circumstance.

  Several times had Waldron had audience with His Majesty, but wascompelled to confess that he had nothing to report, while from Viennacame the secret information daily that, though a great army had beenmobilised, the "manoeuvres" had not yet commenced.

  The very silence was full of menace.

  More than once--at Court, at the Embassy, and in the princelydrawing-rooms of Rome--Hubert had met Her Highness. He had stood besideher full of love and admiration, at the same time puzzled at thepaleness of her countenance and the constant anxiety which seemed everexpressed there. Since that night when he had delivered Pujalet's noteto her she had never seemed the same.

  Yet she would tell him nothing--absolutely nothing. It was her secret,she said--a secret which she steadily declined to divulge.

  "Why do you not take my advice and leave Rome?" she asked one night whenshe was dancing with him at a great ball at the Rospigliosi Palace."You are in constant peril."

  "I have my duties here," was his answer. "I cannot leave."

  She sighed, and as he held her in his arms he felt that she wastrembling.

  "Why won't you heed me?" she implored, looking up at him with thosewonderful eyes of hers. "Do."

  "Because I am not my own master," was his reply. "Because I cannot."

  General Cataldi was there, in his fine uniform resplendent with starsand ribbons, and it chanced that at that moment his eyes fell upon thehandsome pair.

  He regarded them suspiciously, thoughtfully stroking his whitemoustache.

  "That Englishman, Waldron, seems on very friendly terms with thePrincess Luisa," he remarked to the brilliant, handsomely dressed youngwoman at his side--the Countess Cioni.

  "Yes," was the answer of the lady in pink in the glittering tiara. "I,too, have noticed it. But Luisa is always making queer friendships."

  "He was whispering to her a moment ago, just before they commenced todance," the General remarked. "Has Her Highness ever mentioned him?"

  "Oh yes. They met up the Nile, I understand, when Luisa was sent awayfrom Court in disgrace."

  "Ah! then the friendship has be
en of some duration--eh?" grunted HisExcellency, casting another strangely suspicious look at the pair as heturned away.

  Late one night, about a week later, Hubert had been to an officialdinner at the Russian Embassy, in the Via Gaeta, and the weather beingbright and starlight he threw his cloak over his uniform and, lighting acigar, started to stroll home.

  It was past one o'clock and few people were astir in those narrow,ill-lit Italian streets with their high, dark houses. He had turnedfrom the Via Gaeta into the narrow Via Curtatone on his way towards thePiazza del Cinquecento--which was the shortest cut to his rooms--when,ere he was aware of it, a dark figure lurched suddenly out of a doorwayand he was dealt a stunning blow at the back of the head,