Nothing could be more natural than the sequence of events as narrated by this lady, and nothing stranger than the result when viewed, for instance, by Mr.
Lestrade of Scotland Yard." "You were not yourself at fault at all, then ?" "From the first, two facts were very obvious to me, the one that the lady had been quite willing to undergo the wedding ceremony, the other that she had repented of it within a few minutes of returning home.

Obviously something had occurred during the morning, then, to cause her to change her mind.

What could that something be?
She could not have spoken to anyone when she was out, for she had been in the company of the bridegroom.

Had she seen someone, then?
If she had, it must be someone from America because she had spent so short a time in this country that she could hardly have allowed anyone to acquire so deep an influence over her that the mere sight of him would induce her to change her plans so completely.

You see we have already arrived, by a process of exclusion, at the idea that she might have seen an American.