all this time while his friends were trying to prove his innocence, keith was mewed up in prison, having now been there a week. the disgrace of being arrested on such a charge had aged him considerably, and his face had changed from a healthy bronzed colour to a waxen paleness, while the circles under his eyes, and the deep lines furrowing his brow, showed how deeply he was affected by the position in which he found himself.

he steadily denied that he committed the crime imputed to him, and regarding the knife found by villiers, could only say that, after putting it in his pocket at the club, he thought no more of it till next morning, when, having occasion to use it, he found it had disappeared.

some time after the interview with kitty, when she told how keith had stolen the diamonds, eugénie was admitted to the presence of her unfortunate lover. she had tried to see him before, but had always been refused; so when she did gain her object at last, and they stood face to face, both were so overcome with emotion that they could hardly speak. keith held out his arms to her, with a smile on his wan face, and with an inarticulate cry she flung herself on his breast, weeping bitterly.

"don't cry, dear," he said soothingly, making her sit down on the bed. "there! there!" and he quieted her as if she had been a little child.

"i can't help it," she said, drying her eyes; "it seems so terrible to see you here."

"no doubt," replied keith quietly; "but i know i am innocent, and that robs the disgrace of a good deal of its sting."

"i know you are innocent," answered eugénie, "but how to prove it; i thought things would have turned out all right; but when we saw kitty marchurst--"

"she said i had stolen her diamonds," finished stewart, with a satirical laugh. "i've no doubt she fully believes it, and i thank her for having held her tongue so long; but she was never more mistaken in her life. i did put meg back to bed, but i came down the stairs again, and did not leave the room by the window."

"but how is it the child saw you? of course, you know--"

"i know everything. yes. naball told me all. meg says she saw a man she thought was me getting out of the window. i've no doubt she did see a man, but not me."

"but why should she think it you?" asked eugénie, puzzled.

"simply in this way. i put her to bed when she was half-asleep, and she knew i was in the room with her. when i left, she fell asleep, and as her slumber was fitful, as i am sure it was, seeing she came downstairs, she no doubt woke up at the sound of the window being opened, and saw a man getting out. you know how an hour's sleep passes as a moment when one wakes, so i've no doubt meg thought she'd just closed her eyes, and opened them again to see me getting out of the window."

"i understand," said eugénie; "but who could it have been?"

"i believe it was villiers," observed keith thoughtfully. "he was about the house on that night; he was in want of money, so no doubt when caprice left him in the supper-room, he walked upstairs to the bedroom, stole the diamonds, and left by the window. he could easily do this, as every one was in the drawing-room. then naball found that diamond clasp in his possession, or, at least, in the possession of the chinaman to whom he sold it."

"but if he sold all those diamonds to old lazarus, he must have got a good deal of money for them. why did he not leave the country?"

keith sighed.

"i'm sure i don't know. it seems all so mysterious," he said dismally. "what do you think should be done, eugénie?"

"i think i'll see naball again, or some other detective, and sift the whole affair to the bottom."

keith looked at her with a pitying smile.

"my dear child, that will cost a lot of money, and you have not--"

eugénie gave a laugh. she was not going to tell him just yet, so she gave an evasive answer.

"i've got my salary," she said gaily. "some of it was paid to me the other day. see!" and taking out her purse, she emptied it into his hand.

"oh! what a lot of money," said keith smiling. "a five-pound note, three sovereigns, and two one-pound notes."

"which makes exactly ten pounds," remarked eugénie, with a smile; "and i'm going to pay it all away to naball, to get you out of this trouble."

stewart, kissed her, and smoothed out the notes one after the other.

"it's no use, eugénie," he said, offering her the notes back; "it will take more than that to help me; besides, you forget i have five hundred pounds in the bank."

"yes," she said, turning away her face; "five hundred."

"and you'll have it--if--if i die."

she turned to him, and threw her arms round his neck.

"oh, my darling! my darling!" she cried vehemently, "why do you say such things? you will not die. you will live to be happy and famous."

"famous!" he said bitterly, "no; i'm not famous yet, but notorious enough. there's only one chance of escape for me."

"and that is?"

"to trace those notes that were stolen--twenty five-pound notes like this," taking up the five-pound note.

"but you haven't got the numbers."

"no; but, as i told naball, that boy wrote something on the back of one of them." here keith turned over the five-pound note; and then, giving a cry of surprise, sprang to his feet. "eugénie, look, look!"

she snatched the note from him, and there on the back were traced in ink the words, "back flat-iron."

"one of the notes," said keith hoarsely. "one of the notes stolen on that night by the person who murdered jacob lazarus."

eugénie had also risen to her feet and her face wore a look of horror. she looked at her lover, and he looked back again, with the same name in their thoughts.

"kitty marchurst!"

"good god!" said stewart, moistening his dry lips with his tongue, "can she be guilty, after all?"

"i can't believe it," said eugénie determinedly, "though naball says he thinks she did it. but i certainly got this note from her."

"she may have received it from some one else," cried keith eagerly. "god knows, i don't want to die myself, but to put the rope round the neck of that unhappy woman--horrible," and he covered his face with his hands.

eugénie put on her gloves, and then touched his arm.

"i'm going," she said in a quiet voice.

"going?" he repeated, springing to his feet.

"yes, to see naball, and show him the note."

"but kitty marchurst!"

"don't trouble about her," said eugénie, a trifle coldly. "she is all right, and i've no doubt can explain where she got this note. wherever it was, you can depend it was not from the dead man's safe. good-bye, keith," kissing him. "this note gives us the clue, and before many days are over you will be free, and the murderer of jacob lazarus will be in this cell."