There was neither person nor thing to be seen behind him.

He turned back again to the woman.

The woman had left him, under the influence of some sudden panic.

She was hurrying away from him--running, old as she was--flying the sight of him, as if the sight of him was the pestilence.
"Mad!" he thought--and turned his back on the sight of her.
He found himself (hardly knowing how he had got there) under the walnut-tree once more.

In a few minutes his hardy nerves had recovered themselves--he could laugh over the remembrance of the strange impression that had been produced on him.