the duke shut the door and leant against it, listening anxiously, breathing quickly. there came the bang of the front door. with a deep sigh of relief he left the door, came briskly, smiling, across the room, and put the card-case back into the pocket of guerchard's cloak. he lighted a cigarette, dropped into an easy chair, and sat waiting with an entirely careless air for the detective's return. presently he heard quick footsteps on the bare boards of the empty room beyond the opening. then guerchard came down the steps and out of the fireplace.

his face wore an expression of extreme perplexity:

"i can't understand it," he said. "i found nothing."

"nothing?" said the duke.

"no. are you sure you saw the handkerchief in one of those little rooms on the second floor—quite sure?" said guerchard.

"of course i did," said the duke. "isn't it there?"

"no," said guerchard.

"you can't have looked properly," said the duke, with a touch of irony in his voice. "if i were you, i should go back and look again."

"no. if i've looked for a thing, i've looked for it. there's no need for me to look a second time. but, all the same, it's rather funny. doesn't it strike you as being rather funny, your grace?" said guerchard, with a worried air.

"it strikes me as being uncommonly funny," said the duke, with an ambiguous smile.

guerchard looked at him with a sudden uneasiness; then he rang the bell.

bonavent came into the room.

"mademoiselle kritchnoff, bonavent. it's quite time," said guerchard.

"mademoiselle kritchnoff?" said bonavent, with an air of surprise.

"yes, it's time that she was taken to the police-station."

"mademoiselle kritchnoff has gone, sir," said bonavent, in a tone of quiet remonstrance.

"gone? what do you mean by gone?" said guerchard.

"gone, sir, gone!" said bonavent patiently.

"but you're mad.... mad!" cried guerchard.

"no, i'm not mad," said bonavent. "gone! but who let her go?" cried guerchard.

"the men at the door," said bonavent.

"the men at the door," said guerchard, in a tone of stupefaction. "but she had to have my permit ... my permit on my card! send the fools up to me!"

bonavent went to the top of the staircase, and called down it. guerchard followed him. two detectives came hurrying up the stairs and into the drawing-room.

"what the devil do you mean by letting mademoiselle kritchnoff leave the house without my permit, written on my card?" cried guerchard violently.

"but she had your permit, sir, and it was written on your card," stammered one of the detectives.

"it was? ... it was?" said guerchard. "then, by jove, it was a forgery!"

he stood thoughtful for a moment. then quietly he told his two men to go back to their post. he did not stir for a minute or two, puzzling it out, seeking light.

then he came back slowly into the drawing-room and looked uneasily at the duke. the duke was sitting in his easy chair, smoking a cigarette with a listless air. guerchard looked at him, and looked at him, almost as if he now saw him for the first time.

"well?" said the duke, "have you sent that poor child off to prison? if i'd done a thing like that i don't think i should sleep very well, m. guerchard."

"that poor child has just escaped, by means of a forged permit," said guerchard very glumly.

"by jove, i am glad to hear that!" cried the duke. "you'll forgive my lack of sympathy, m. guerchard; but she was such a child."

"not too young to be lupin's accomplice," said guerchard drily.

"you really think she is?" said the duke, in a tone of doubt.

"i'm sure of it," said guerchard, with decision; then he added slowly, with a perplexed air:

"but how—how—could she get that forged permit?"

the duke shook his head, and looked as solemn as an owl. guerchard looked at him uneasily, went out of the drawing-room, and shut the door.

"how long has mademoiselle kritchnoff been gone?" he said to bonavent.

"not much more than five minutes," said bonavent. "she came out from talking to you in the drawing-room—"

"talking to me in the drawing-room!" exclaimed guerchard.

"yes," said bonavent. "she came out and went straight down the stairs and out of the house."

a faint, sighing gasp came from guerchard's lips. he dashed into the drawing-room, crossed the room quickly to his cloak, picked it up, took the card-case out of the pocket, and counted the cards in it. then he looked at the duke.

the duke smiled at him, a charming smile, almost caressing.

there seemed to be a lump in guerchard's throat; he swallowed it loudly.

he put the card-case into the breast-pocket of the coat he was wearing. then he cried sharply, "bonavent! bonavent!"

bonavent opened the door, and stood in the doorway.

"you sent off victoire in the prison-van, i suppose," said guerchard.

"oh, a long while ago, sir," said bonavent.

"the van had been waiting at the door since half-past nine."

"since half-past nine? ... but i told them i shouldn't want it till a quarter to eleven. i suppose they were making an effort to be in time for once. well, it doesn't matter," said guerchard.

"then i suppose i'd better send the other prison-van away?" said bonavent.

"what other van?" said guerchard.

"the van which has just arrived," said bonavent.

"what! what on earth are you talking about?" cried guerchard, with a sudden anxiety in his voice and on his face.

"didn't you order two prison-vans?" said bonavent.

guerchard jumped; and his face went purple with fury and dismay. "you don't mean to tell me that two prison-vans have been here?" he cried.

"yes, sir," said bonavent.

"damnation!" cried guerchard. "in which of them did you put victoire? in which of them?"

"why, in the first, sir," said bonavent.

"did you see the police in charge of it? the coachman?"

"yes, sir," said bonavent.

"did you recognize them?" said guerchard.

"no," said bonavent; "they must have been new men. they told me they came from the sante."

"you silly fool!" said guerchard through his teeth. "a fine lot of sense you've got."

"why, what's the matter?" said bonavent.

"we're done, done in the eye!" roared guerchard. "it's a stroke—a stroke—"

"of lupin's!" interposed the duke softly.

"but i don't understand," said bonavent.

"you don't understand, you idiot!" cried guerchard. "you've sent victoire away in a sham prison-van—a prison-van belonging to lupin. oh, that scoundrel! he always has something up his sleeve."

"he certainly shows foresight," said the duke. "it was very clever of him to foresee the arrest of victoire and provide against it."

"yes, but where is the leakage? where is the leakage?" cried guerchard, fuming. "how did he learn that the doctor said that she would recover her wits at ten o'clock? here i've had a guard at the door all day; i've imprisoned the household; all the provisions have been received directly by a man of mine; and here he is, ready to pick up victoire the very moment she gives herself away! where is the leakage?"

he turned on bonavent, and went on: "it's no use your standing there with your mouth open, looking like a fool. go upstairs to the servants' quarters and search victoire's room again. that fool of an inspector may have missed something, just as he missed victoire herself. get on! be smart!"

bonavent went off briskly. guerchard paced up and down the room, scowling.

"really, i'm beginning to agree with you, m. guerchard, that this lupin is a remarkable man," said the duke. "that prison-van is extraordinarily neat."

"i'll prison-van him!" cried guerchard. "but what fools i have to work with. if i could get hold of people of ordinary intelligence it would be impossible to play such a trick as that."

"i don't know about that," said the duke thoughtfully. "i think it would have required an uncommon fool to discover that trick."

"what on earth do you mean? why?" said guerchard.

"because it's so wonderfully simple," said the duke. "and at the same time it's such infernal cheek."

"there's something in that," said guerchard grumpily. "but then, i'm always saying to my men, 'suspect everything; suspect everybody; suspect, suspect, suspect.' i tell you, your grace, that there is only one motto for the successful detective, and that is that one word, 'suspect.'"

"it can't be a very comfortable business, then," said the duke. "but i suppose it has its charms."

"oh, one gets used to the disagreeable part," said guerchard.

the telephone bell rang; and he rose and went to it. he put the receiver to his ear and said, "yes; it's i—chief-inspector guerchard."

he turned and said to the duke, "it's the gardener at charmerace, your grace."

"is it?" said the duke indifferently.

guerchard turned to the telephone. "are you there?" he said. "can you hear me clearly? ... i want to know who was in your hot-house yesterday ... who could have gathered some of your pink salvias?"

"i told you that it was i," said the duke.

"yes, yes, i know," said guerchard. and he turned again to the telephone. "yes, yesterday," he said. "nobody else? ... no one but the duke of charmerace? ... are you sure?... quite sure?... absolutely sure? ... yes, that's all i wanted to know ... thank you."

he turned to the duke and said, "did you hear that, your grace? the gardener says that you were the only person in his hot-houses yesterday, the only person who could have plucked any pink salvias."

"does he?" said the duke carelessly.

guerchard looked at him, his brow knitted in a faint, pondering frown. then the door opened, and bonavent came in: "i've been through victoire's room," he said, "and all i could find that might be of any use is this—a prayer-book. it was on her dressing-table just as she left it. the inspector hadn't touched it."

"what about it?" said guerchard, taking the prayer-book.

"there's a photograph in it," said bonavent. "it may come in useful when we circulate her description; for i suppose we shall try to get hold of victoire."

guerchard took the photograph from the prayer-book and looked at it: "it looks about ten years old," he said. "it's a good deal faded for reproduction. hullo! what have we here?"

the photograph showed victoire in her sunday best, and with her a boy of seventeen or eighteen. guerchard's eyes glued themselves to the face of the boy. he stared at it, holding the portrait now nearer, now further off. his eyes kept stealing covertly from the photograph to the face of the duke.

the duke caught one of those covert glances, and a vague uneasiness flickered in his eyes. guerchard saw it. he came nearer to the duke and looked at him earnestly, as if he couldn't believe his eyes.

"what's the matter?" said the duke. "what are you looking at so curiously? isn't my tie straight?" and he put up his hand and felt it.

"oh, nothing, nothing," said guerchard. and he studied the photograph again with a frowning face.

there was a noise of voices and laughter in the hall.

"those people are going," said the duke. "i must go down and say good-bye to them." and he rose and went out of the room.

guerchard stood staring, staring at the photograph.

the duke ran down the stairs, and said goodbye to the millionaire's guests. after they had gone, m. gournay-martin went quickly up the stairs; germaine and the duke followed more slowly.

"my father is going to the ritz to sleep," said germaine, "and i'm going with him. he doesn't like the idea of my sleeping in this house to-night. i suppose he's afraid that lupin will make an attack in force with all his gang. still, if he did, i think that guerchard could give a good account of himself—he's got men enough in the house, at any rate. irma tells me it's swarming with them. it would never do for me to be in the house if there were a fight."

"oh, come, you don't really believe that lupin is coming to-night?" said the duke, with a sceptical laugh. "the whole thing is sheer bluff—he has no more intention of coming tonight to steal that coronet than—than i have."

"oh, well, there's no harm in being on the safe side," said germaine. "everybody's agreed that he's a very terrible person. i'll just run up to my room and get a wrap; irma has my things all packed. she can come round tomorrow morning to the ritz and dress me."

she ran up the stairs, and the duke went into the drawing-room. he found guerchard standing where he had left him, still frowning, still thinking hard.

"the family are off to the ritz. it's rather a reflection on your powers of protecting them, isn't it?" said the duke.

"oh, well, i expect they'd be happier out of the house," said guerchard. he looked at the duke again with inquiring, searching eyes.

"what's the matter?" said the duke. "is my tie crooked?"

"oh, no, no; it's quite straight, your grace," said guerchard, but he did not take his eyes from the duke's face.

the door opened, and in came m. gournay-martin, holding a bag in his hand. "it seems to be settled that i'm never to sleep in my own house again," he said in a grumbling tone.

"there's no reason to go," said the duke. "why are you going?"

"danger," said m. gournay-martin. "you read lupin's telegram: 'i shall come to-night between a quarter to twelve and midnight to take the coronet.' he knows that it was in my bedroom. do you think i'm going to sleep in that room with the chance of that scoundrel turning up and cutting my throat?"

"oh, you can have a dozen policemen in the room if you like," said the duke. "can't he, m. guerchard?"

"certainly," said guerchard. "i can answer for it that you will be in no danger, m. gournay-martin."

"thank you," said the millionaire. "but all the same, outside is good enough for me."

germaine came into the room, cloaked and ready to start.

"for once in a way you are ready first, papa," she said. "are you coming, jacques?"

"no; i think i'll stay here, on the chance that lupin is not bluffing," said the duke. "i don't think, myself, that i'm going to be gladdened by the sight of him—in fact, i'm ready to bet against it. but you're all so certain about it that i really must stay on the chance. and, after all, there's no doubt that he's a man of immense audacity and ready to take any risk."

"well, at any rate, if he does come he won't find the diadem," said m. gournay-martin, in a tone of triumph. "i'm taking it with me—i've got it here." and he held up his bag.

"you are?" said the duke.

"yes, i am," said m. gournay-martin firmly.

"do you think it's wise?" said the duke.

"why not?" said m. gournay-martin.

"if lupin's really made up his mind to collar that coronet, and if you're so sure that, in spite of all these safeguards, he's going to make the attempt, it seems to me that you're taking a considerable risk. he asked you to have it ready for him in your bedroom. he didn't say which bedroom."

"good lord! i never thought of that!" said m. gournay-martin, with an air of sudden and very lively alarm.

"his grace is right," said guerchard. "it would be exactly like lupin to send that telegram to drive you out of the house with the coronet to some place where you would be less protected. that is exactly one of his tricks."

"good heavens!" said the millionaire, pulling out his keys and unlocking the bag. he opened it, paused hesitatingly, and snapped it to again.

"half a minute," he said. "i want a word with you, duke."

he led the way out of the drawing-room door and the duke followed him. he shut the door and said in a whisper:

"in a case like this, i suspect everybody."

"everybody suspects everybody, apparently," said the duke. "are you sure you don't suspect me?"

"now, now, this is no time for joking," said the millionaire impatiently. "what do you think about guerchard?"

"about guerchard?" said the duke. "what do you mean?"

"do you think i can put full confidence in guerchard?" said m. gournay-martin.

"oh, i think so," said the duke. "besides, i shall be here to look after guerchard. and, though i wouldn't undertake to answer for lupin, i think i can answer for guerchard. if he tries to escape with the coronet, i will wring his neck for you with pleasure. it would do me good. and it would do guerchard good, too."

the millionaire stood reflecting for a minute or two. then he said, "very good; i'll trust him."

hardly had the door closed behind the millionaire and the duke, when guerchard crossed the room quickly to germaine and drew from his pocket the photograph of victoire and the young man.

"do you know this photograph of his grace, mademoiselle?" he said quickly.

germaine took the photograph and looked at it.

"it's rather faded," she said.

"yes; it's about ten years old," said guerchard.

"i seem to know the face of the woman," said germaine. "but if it's ten years old it certainly isn't the photograph of the duke."

"but it's like him?" said guerchard.

"oh, yes, it's like the duke as he is now—at least, it's a little like him. but it's not like the duke as he was ten years ago. he has changed so," said germaine.

"oh, has he?" said guerchard.

"yes; there was that exhausting journey of his—and then his illness. the doctors gave up all hope of him, you know."

"oh, did they?" said guerchard.

"yes; at montevideo. but his health is quite restored now."

the door opened and the millionaire and the duke came into the room. m. gournay-martin set his bag upon the table, unlocked it, and with a solemn air took out the case which held the coronet. he opened it; and they looked at it.

"isn't it beautiful?" he said with a sigh.

"marvellous!" said the duke.

m. gournay-martin closed the case, and said solemnly:

"there is danger, m. guerchard, so i am going to trust the coronet to you. you are the defender of my hearth and home—you are the proper person to guard the coronet. i take it that you have no objection?"

"not the slightest, m. gournay-martin," said guerchard. "it's exactly what i wanted you to ask me to do."

m. gournay-martin hesitated. then he handed the coronet to guerchard, saying with a frank and noble air, "i have every confidence in you, m. guerchard."

"thank you," said guerchard.

"good-night," said m. gournay-martin.

"good-night, m. guerchard," said germaine.

"i think, after all, i'll change my mind and go with you. i'm very short of sleep," said the duke. "good-night, m. guerchard."

"you're never going too, your grace!" cried guerchard.

"why, you don't want me to stay, do you?" said the duke.

"yes," said guerchard slowly.

"i think i would rather go to bed," said the duke gaily.

"are you afraid?" said guerchard, and there was challenge, almost an insolent challenge, in his tone.

there was a pause. the duke frowned slightly with a reflective air. then he drew himself up; and said a little haughtily:

"you've certainly found the way to make me stay, m. guerchard."

"yes, yes; stay, stay," said m. gournay-martin hastily. "it's an excellent idea, excellent. you're the very man to help m. guerchard, duke. you're an intrepid explorer, used to danger and resourceful, absolutely fearless."

"do you really mean to say you're not going home to bed, jacques?" said germaine, disregarding her father's wish with her usual frankness.

"no; i'm going to stay with m. guerchard," said the duke slowly.

"well, you will be fresh to go to the princess's to-morrow night." said germaine petulantly. "you didn't get any sleep at all last night, you couldn't have. you left charmerace at eight o'clock; you were motoring all the night, and only got to paris at six o'clock this morning."

"motoring all night, from eight o'clock to six!" muttered guerchard under his breath.

"oh, that will be all right," said the duke carelessly. "this interesting affair is to be over by midnight, isn't it?"

"well, i warn you that, tired or fresh, you will have to come with me to the princess's to-morrow night. all paris will be there—all paris, that is, who are in paris."

"oh, i shall be fresh enough," said the duke.

they went out of the drawing-room and down the stairs, all four of them. there was an alert readiness about guerchard, as if he were ready to spring. he kept within a foot of the duke right to the front door. the detective in charge opened it; and they went down the steps to the taxi-cab which was awaiting them. the duke kissed germaine's fingers and handed her into the taxi-cab.

m. gournay-martin paused at the cab-door, and turned and said, with a pathetic air, "am i never to sleep in my own house again?" he got into the cab and drove off.

the duke turned and came up the steps, followed by guerchard. in the hall he took his opera-hat and coat from the stand, and went upstairs. half-way up the flight he paused and said:

"where shall we wait for lupin, m. guerchard? in the drawing-room, or in m. gournay-martin's bedroom?"

"oh, the drawing-room," said guerchard. "i think it very unlikely that lupin will look for the coronet in m. gournay-martin's bedroom. he would know very well that that is the last place to find it now."

the duke went on into the drawing-room. at the door guerchard stopped and said: "i will just go and post my men, your grace."

"very good," said the duke; and he went into the drawing-room.

he sat down, lighted a cigarette, and yawned. then he took out his watch and looked at it.

"another twenty minutes," he said.