if there was a dark mystery any longer it was confined to the corner house now. hetty was not likely to see any more of lytton avenue. it was fortunate for her that mamie was so much better in the morning, for as soon as the business of the day had commenced there was a rush of people to lytton avenue.

they poured in thick and fast till the law intervened in the person of a posse of officials who represented the sheriff of london, and then hetty was permitted to pack up her belongings and those of the child and depart. gilbert lawrence received them with open arms. bruce was there, pleased enough to get hetty from the house where she had suffered so much. but there was a white despairing look that caused hetty to forget her own troubles.

the white look did not even vanish when hetty spoke of her previous night's adventure.

"it was part of a plot to ruin us both," bruce said moodily. "i should have been charged with criminal carelessness, which is fatal to a doctor, and you would have been guilty of administering an overdose. that woman, we know who she was, changed the bottles once and would have changed them again, in fact that is why she returned--the countess."

"oh, no," hetty cried. "she never could have done that. her own child, bruce? fancy a mother sacrificing the life of her own child to gratify a vengeance! i could not think as badly of her as that."

bruce smiled wearily.

"are you quite sure," he asked, "that mamie is her own child?"

hetty had no reply for the moment. that idea had never occurred to her before. certainly she had never looked upon the countess as a model mother; indeed, she had never seen her display what might be called natural affection.

"we shall probably never know," she said after a pause. "but as to your own trouble, gordon, dear gordon, why don't you confide in me?"

the appeal in the thrilling tender voice touched him. he took the slim figure in his arms and kissed the red lips.

"it's ruin," he said simply, "nothing else. a little time ago it looked to me as if all my ambitions were to be realised. and then this crushing misfortune comes upon me. my practice falls away, and i could not get my money in. of course i can't dun patients like mine. it didn't matter till lately, because the guineas i got from consultations were keeping me going. but these morning callers call no more. i was pressed here and there, and i borrowed money."

"not from those people who advertise, gordon?"

"i am afraid i was as foolish as that," bruce said, with a faint smile. "that sort of people seem to know when one is under the weather. and there was one very plausible fellow who sent me a confidential letter. i fell into the trap, and if i can't find ￡500 tomorrow i am ruined."

hetty turned pale. but no word of reproach passed her lips. it was no time for that. and she knew by repute the kind of creditor that gordon had. she merely asked the name of the obdurate creditor.

"i shall find some way out of it," she said. "now go back to your work. courage, dearest."

she kissed him tenderly, and pushed him from the room. already she had made up her mind exactly what to do. mamie must sit down and be good till teatime, after which she should go in the park and feed the swans. half an hour later and hetty was calling upon izaac isidore to ask his advice.

isidore received his visitor warmly. he had taken a great fancy in his calm way to the pretty, plucky girl who had played so fine a part in the elucidation of a great mystery and a cruel wrong. he listened to what hetty had to say.

"i thought you would find a way out," she suggested.

"well, so i can," isidore smiled. "i am not going to offer to lend that young man money, because that would wound his pride. besides, there will be no occasion. now, can you let me know the name of bruce's creditor."

hetty gave the desired information. there was a peculiar smile on the face of her companion.

"i fancy i can see my way to settle this business," he said. "in my early days i saw a deal of the shady side of finance--as a lad i was in the office of one of the very worst of them. i know all about this fellow. he is going to climb down, he is going to take a reasonable rate of interest, and he is going to give your lover time. you can make your mind easy about that."

and isidore pulled at his cigar thoughtfully. he seemed so strong and confident that hetty was strangely comforted.

"i thought i could rely upon you," she said gratefully. "mr. isidore, you have taken a great load from my mind."

isidore finished his cigar, after which he took a frugal omnibus to the city, getting down in the neighbourhood of cheapside. he found himself presently in a dingy office off ironmonger lane, and face to face with a fat, oily man, who recognized him with a mixture of admiration and apprehension.

"it's about that business of dr. gordon bruce," isidore said curtly. "now, my friend wolffman, you know me and i know you. i don't want to ruin you body and bones, but i shall do so unless you listen to reason. you are going to write to dr. bruce, and tell him the matter shall stand over for the present----"

"but my principal!" gasped wolffman. "the lady who is paying me----"

"to ruin dr. bruce," isidore said, as coolly as if a great light had not suddenly broken in upon him. "so your friend is in london?"

wolffman wriggled uneasily. he wanted to lie badly, but with those eyes upon him he could not do so.

"she was yesterday," he stammered.

"ah, then, you must dissemble with her. tell her any lie you like so long as you let dr. bruce alone. i guessed there was some scheme on hand when i heard that you had written to the doctor. goodbye, wolffman, and recollect that your ruin or otherwise depends upon yourself."

isidore went out smiling blandly. he had made a great discovery.

"the countess again," he murmured. "she's in this, as i thought. and so she is still in london, after all. how interested prout will be!"