in, folding his hands
above his plate. "I assure you I am far from abandoning reason. I am
certain he is innocent, and I always was certain of it, because of
something that I know, and knew from the very beginning. You asked me
just now to imagine myself on the jury at Marlowe's trial. That would be
an unprofitable exercise of the mental powers, because I know that I
should be present in another capacity. I should be in the witness box,
giving evidence for the defense. You said just now, 'If there were a
single piece of evidence in support of his tale.' There is, and it is my
evidence. And," he added quietly, "it is conclusive." He took up his
knife and fork and went contentedly on with his dinner.

The pallor of excitement had turned Trent to marble while Mr. Cupples
led laboriously up to this statement. At the last word the blood rushed
to his face again and he struck the table with an unnatural laugh. "It
can't be!" he exploded. "It's something you fancied, something you
dreamed after one of those debauches of soda-and-milk. You can't really
mean that all the time I was working on the case down there you knew
Marlowe was innocent."

Mr. Cupples, busy with his last mouthful, nodded brightly. He made an
end of eating, wiped his sparse mustache, and then leaned forward over
the table. "It's very simple," he said. "I shot Manderson myself."

* * * * *

"I am afraid I startled you," Trent heard the voice of Mr. Cupples say.
He forced himself out of his stupefaction like a diver striking upward
for the surface, and with a rigid movement raised his glass. But half of
the wine splashed upon the cloth, and he put it carefully down again
untasted. He drew a deep breath, which was exhaled in a laugh wholly
without merriment. "Go on," he said.

"It was not murder," began Mr. Cupples, slowly measuring off inches with
a fork on the edge of the table. "I will tell you the whole story. On
that Sunday night I was taking my before-bedtime constitutional, having
set out from the hotel about a quarter past ten. I went along the
field-path that runs behind White Gables, cutting off the great curve of
the road, and came out on the road nearly opposite that gate that is
just by the eighth hole on the golf-course. Then I turned in there,
meaning to walk along the turf to the edge of the cliff, and go back
that way. I had only gone a few steps when I heard the car coming, and
then I heard it stop near the