"It would prove your astuteness, Mr. Delverton," said Quarles. "Mine
would be only the spade work which any one can do when he has been told
how. Perhaps you will let me explain in my own way, and I will go over
the old ground as little as possible, since we three are aware of the
main facts and the investigations which originally took place. First,
then, the manner of Mr. Farrell's death. Now, since he was found in his
own private office, sitting at his own desk, with a tumbler beside him,
it is evident that if he did not commit suicide it was intended that it
should appear as if he had done so. To believe it a case of suicide is
the simplest solution. He could enter the office by the side door at his
will, he could poison himself there at his leisure, and it would never
occur to him to imagine that any one would afterwards suspect he had met
his death in any other way. The one thing missing is the motive. The only
person even to suggest that Farrell had looked worried was the junior
clerk, Small, and his uncorroborated opinion does not count for much.
Besides, his affairs were in order, and he was about to be married. You
must stop me, Mr. Delverton, if I make any incorrect statements."

"Certainly. So far you have merely repeated what every one knows."

"Except in one minor particular," said Quarles. "I lay special emphasis
on the desire of some one to show that it was a case of suicide. If we
deny suicide this becomes an important point, for we have to enquire when
and how the poison was administered. Did Farrell at some time before
midnight bring some one back to the office with him? For what purpose was
he brought there? How was the poison administered? We have evidence that
it was not drunk out of the glass on the table, no trace of poison being
found, and we can hardly suppose that Farrell would swallow a tablet at
any one's bidding. Since there was an evident desire to make it appear a
case of suicide, we should expect to find traces of poison in the glass;