I don't myself see how you can get behind the portrait and the lady's own confession." "You couldn't possibly have mistaken about that, could you?
I mean she couldn't have been confessing anything else which you could have taken up to mean murder ?" "No, she couldn't.

In the first place, it isn't at all likely that there would be two attractive-looking lady criminals, travelling about in trains at the same time, both wanting to confess what they had done.
In the second place, her crime must have been pretty serious, for she was particularly anxious to find out whether it was likely to shock you." "Me ?" "Yes, you.

She mentioned you by name, and asked particularly whether you'd be likely to be shocked, when you found out who she was.

Now, if she had simply been slipping trifling articles off shop counters into her muff, she wouldn't have expected you to be shocked.

That's what makes me say her crime was a serious one." "Still," said the Major, "even supposing she really was afraid of shocking me; though I can't see how she came to consider me at all--" "She did.