As regards the difficulty, Stoner had somehow or other got a vague idea, that evening of the murder, that something was wrong with Cotherstone.

He had noticed, or thought he noticed, a queer look on old Kitely's face when the ex-detective left the private room--it was a look of quiet satisfaction, or triumph, or malice; any way, said Stoner, it was something.

Then there was the fact of Cotherstone's curious abstraction when he, Stoner, entered and found his employer sitting in the darkness, long after Kitely had gone--Cotherstone had said he was asleep, but Stoner knew that to be a fib.

Altogether, Stoner had gained a vague feeling, a curious intuition, that there was something queer, not unconnected with the visit of Cotherstone's new tenant, and when he heard, next morning, of what had befallen Kitely, all his suspicions were renewed.
So much for the difficult reasons which had made him appropriate the half-sheet of foolscap.

But there was a reason which was not difficult.
It lay in the presence of that word _Wilchester_.