Perhaps the thought of that lonely walk across the ill-omened moor was weighing heavily upon his mind.
As I watched them Stapleton rose and left the room, while Sir Henry filled his glass again and leaned back in his chair, puffing at his cigar.

I heard the creak of a door and the crisp sound of boots upon gravel.

The steps passed along the path on the other side of the wall under which I crouched.

Looking over, I saw the naturalist pause at the door of an out-house in the corner of the orchard.

A key turned in a lock, and as he passed in there was a curious scuffling noise from within.