in the way I have described.
Each parcel was to cost ten pounds and to contain no less than ten
diamonds. No money passed between them, but every time a parcel was
put through the tunnel, the confederate on the other side put a blue
bead in its place among the sand. The boy found the bead and kept it
as a receipt, and when he came out at the end of every three months'
contract he wore a bracelet of blue beads on his wrist. Naturally, the
authorities didn't take any notice of this when they searched him, for
nearly all Kafirs wear beads of some kind. These beads were quite a
common kind to look at; only when they were examined carefully were
they found to have been passed through some chemical process which dyed
the inside a peculiar mauve colour, making it impossible for the Kafir
to cheat by adding ordinary blue beads (of which there are plenty for
sale in the compound) to his little bunch of 'receipts.'"

"How clever!" said Rosanne. "And how are they going to catch the
confederate? Put a trap-parcel, I suppose, and pounce on him when he
comes to fetch it?"

She had seated herself again, opposite Kitty, her arms resting on the
back of the chair, her face vivid with interest.

"Cleverer than that," announced Kitty. "They are going to put the trap
and watch who fetches it. But they won't pounce on him; they mean to
follow him up and arrest the whole gang."

"Gang?"

"Len says there's sure to be a gang of them, and for the sake of
getting them all, parcel after parcel of stones will be put through the
tunnel, if necessary, until every one of them is traced and arrested."

"Rather risky for the diamonds, I should think!"

"They'll only put inferior ones in. Besides, the Kafir boy's contract
is up in a week's time, and if all the gang aren't caught by then,
they're going to let the boy go out and meet his confederate to deliver
his beads, and then the arrest will be made."

"Surely the Kafir was able to describe him, if he had been in the habit
of meeting him every three months?"

"He says he was a young white boy, very thin, who wears a mask and an
overcoat. They have met twice at night, in an old unused house in the
Malay compound, the other side of Kimberley. Can you imagine any one
running such awful risks for the sake of diamonds, Nan? But Len says
it goes on all the time--this illicit diamond-buying business--and the
company loses thousands of pounds every year and is hardly ever able to
catch t