Who knows?
He might have bought it two years before under an inspiration.
Even then, months and months before he met Joan or knew of her existence, this very evening might have been mapped out He was a fatalist, and it fell into his creed to think so.
He didn't wonder why Joan was silent or ask himself jealously of what she was thinking.

He chose to believe that she had arrived at the end of impishness, had grown weary of Harry Oldershaw and his cubbish ways and had turned to himself naturally and with relief, choosing her moment with the uncanny intuition that is the gift of women.

She was only just in time.

To-morrow would have found him following the faithful Alice on her forlorn hope--the incurable man.
It was only when they turned into the narrow sandy road that was within a quarter of a mile of the club at Devon that Joan came out of the numbness that had settled upon her and recognized things that were stamped with the marks of an afternoon that was never to be forgotten.
Martin--Martin--and it was all her fault.
"But why are you coming this way ?" she asked, drawing back into her seat.
"Because my cottage is just here," said Gilbert.
"At Devon ?" "Yes.

Why not?
I had a fancy for playing hermit from time to time.