nd will be here to-morrow, or Monday,
and the officer he has chosen should be on the ground before to-morrow
morning. No doubt he will be all that you wish for, and my duties will
call me elsewhere very soon."

Then they all rise, and standing in a group begin talking. They so much
regret that they can not retain his services, and they are very grateful
to him for so much light as he has thrown upon the subject of the
robbery.

"But wait," he says, "you are to bear in mind that you _have_ no light;
you are in total darkness and ignorance; to-morrow you will have a new
officer, he may evolve a totally different theory. Then discard mine, or
not, as you think fit; in any case, let it be kept exclusively to your
three selves, for I am very likely to make a second appearance here. I
think that these burglars of yours are the chaps I am wanting. And, Miss
Wardour, this reminds me," drawing from his pocket the chloroform vial
wrapped in its accompanying linen bit, "may I keep this until morning? I
will return it to you by Doctor Heath, and, if your officer is not too
much in the way, will try and see you in person, if you will kindly give
me what facts you can recall concerning those robberies."

Constance expresses a hope that the officer will not be in the way, and
after they have talked a little more, the detective repeating his
cautions, Constance repeating her regret that he is not to take the
case, as _her_ case; and Mrs. Aliston repeating everything that comes
into her head, they separate, and the two men, looking so oddly unlike,
go out into the night.

Mrs. Aliston is ready to talk, but Constance is in no mood to listen.
She cuts short her aunt's elocution, and goes with listless weariness to
her own apartments.

Since the appearance of the detective, a shade of perplexity rested on
her face, and over and again her thoughts have repeated the question
which now falls from her lips.

"What does it mean? I am not mistaken; he said, 'here, I am Doctor Heath
from nowhere.' I begin to think that life is a mystery."

For Miss Wardour, hesitating a moment as she passed in from the balcony,
had caught the words uttered for the ears of the detective only.

CHAPTER VI.

DOCTOR HEATH AT HOME.

Doctor Heath and the detective went in silence down the wide
shrub-bordered walk, to the spot where the doctor's horse awaited him.
Here the detective paused suddenly and listened a moment.

"We should not be seen tog