in of lakes artificially produced by
damming up the River Elan, a tributary of the Wye. The great aqueduct
which carries the water from the Elan, eighty miles across country,
travelling through hills and bridging valleys, runs past Ludlow and
Cleobury Mortimer, through the Wyre Forest to Kidderminster, and on to
Birmingham itself through Frankley, where there is a large storage
reservoir from which the water is distributed.

The scenery was bleak and desolate. Before us the sun was sinking in a
flood of crimson light. We walked briskly, the long legs of the Russian
carrying him swiftly over the uneven ground while I trotted beside him.
Before the last rays of the sun had died away we saw the black outline
of the Caban Loch dam before us, and caught the sheen of water beyond.
On the north lay the river Elan and on the south the steep side of a
mountain towered up against the luminous sky. The road runs along the
left bank of the river bounded by a series of bold and abrupt crags that
rise to a height of some eight hundred feet above the level of the
water. Just below the Caban Dam is a house occupied by an inspector in
charge of the gauge apparatus that is used to measure the outflow of
water from the huge natural reservoirs. The lights from his house
twinkled through the growing darkness as we drew near, and we skirted it
by a short detour and pressed on.

"How long does water take to get from here to Birmingham?" asked
Sarakoff as we climbed up to the edge of the first lake.

"It travels about a couple of miles an hour," I replied. "So that means
about a day and a half."

We spoke in low voices, for we were afraid of detection. The presence of
two visitors at that hour might well have attracted attention.

"A day and a half! Then the bacillus has a long journey to take." He
stopped at the margin of the water and stared across the shadowy lake.
"Yes, it has a long journey to take, for it will go round the whole
world."

The last glow in the sky tinted the calm sheet of water a deep blood
colour. Sarakoff opened his bag and took out a couple of tubes.

He pulled the cotton-wool plugs out of the tubes, and with a long wire,
loosened the gelatinous contents. Then, inverting the tubes he flung
them into the lake close to the beginning of the huge aqueduct.

I stared as the tubes vanished from sight, feeling that it was too late
to regret what had now been done, for nothing could collect those
millions of bacilli, t