d important parts. With his brain seeking for a solution of that
possibility, he proceeded to examine the pieces of string.

They were odd lengths of ordinary thick twine, but they all seemed to
consist of loose ends which had been knotted together. It was not until
Colwyn took them out of the compartment that he noticed an amazing
peculiarity about them. Each piece of knotted string was burnt at both
ends.

There are some discoveries which spring into the mind with shattering
swiftness. This was one of them. A revelation seemed to come to Colwyn
as light from the sky at midnight, which, lays everything bare in one
frightful flash.

"Is it possible?"

He felt as though these words rushed from him like a thunder-roll
reverberating through the empty space around him. But his set lips had
not uttered a single sound. With tingling nerves he proceeded to carry
out an experiment. He first laid the wick of the tinder-lighter along
the stock of the pistol, just behind the hammer. He next took up one of
the lengths of string, and pulling back the hammer and the trigger of
the pistol, proceeded to bind them both firmly back with the string,
which he passed twice round the wick. When he had tied the string tight
he lit a match and applied it to the end of the wick which was farthest
from the string. His idea was to see whether this extemporized fuse
would creep along the stock of the pistol, burn the string, and release
the bound cock and trigger.

The wick smouldered and glowed, and began to creep towards the string,
which crossed the stock of the pistol about three inches from the
burning end. Colwyn took out his watch and timed its progress. In four
minutes the first inch of the wick was consumed, and the spark at the
end continued to creep sullenly forward in a dull red glow. In another
eight minutes it reached the string, and Colwyn eagerly watched the
process of the burning of the binding. The string singed, smouldered,
and when nearly severed, sprang apart under the pressure of the hammer
and trigger it had been holding back. The released hammer fell with full
force on the cap on the nipple, and exploded it.

There, then, seemed the explanation. Mrs. Heredith had been shot with
Nepcote's revolver, but it was not the deliberately deadened sound of
that slight weapon which had startled the guests in the dining-room on
the night of the murder. The report they had heard was made by the
heavier pistol in front of him. It