se of his own dull powers of invention--for he found
himself unable to conceive one, much less five such schemes--M. Duquesne
came into the inspector's room.

"Does your chief join us to-night?" inquired Sheffield, on learning that
the famous investigator was in London.

"He may do so, m'sieur; but his plans are uncertain."

Almost immediately afterwards they were joined by Harborne, and all
three, entering one of the taxi-cabs that always are in waiting in the
Yard, set out for Dulwich Village.

The night was very dark, with ample promise of early rain, and as the
cab ran past Westminster Abbey a car ahead swung sharply around
Sanctuary Corner. Harborne, whose business it was to know all about
smart society, reported:

"Old Oppner's big Panhard in front. Going our way--Embankment is 'up.' I
wonder what his Agency men are driving at? Alden's got something up his
sleeve, I'll swear."

"I'd like a peep inside that car," said Sheffield.

Harborne took up the speaking-tube as the cab, in turn, rounded into
Great Smith Street.

"Switch off this inside light," he called to the driver, "and get up as
close alongside that Panhard ahead as you dare. She's not moving fast.
Stick there till I tell you to drop back."

The man nodded, and immediately the gear snatched the cab ahead with a
violent jerk. At a high speed they leapt forward upon the narrow road,
swung out to the off-side to avoid a bus, and closed up to the
brilliantly-lighted car.

It was occupied by two women in picturesque evening toilettes. One of
them was a frizzy haired soubrette and the other a blonde. Both were
conspicuously pretty. The fair girl wore a snow white orchid, splashed
with deepest crimson, pinned at her breast. Her companion, who lounged
in the near corner, her cloak negligently cast about her and one rounded
shoulder against the window, was reading a letter; and Harborne, who
found himself not a foot removed from her, was trying vainly to focus
his gaze upon the writing when the fair girl looked up and started to
find the cab so close. The light of a sudden suspicion leapt into her
eyes as, obedient to the detective's order, the taxi-driver slowed down
and permitted the car to pass. Almost immediately the big Panhard leapt
to renewed speed, and quickly disappeared ahead.

Harborne turned to Inspector Sheffield.

"That was Miss Zoe Oppner, the old man's daughter."

"I know," said Sheffield sharply. "Read any of the letter?"

"No,"