But your theory's a little weak, isn't it?
To get away unseen would be that thief's first preoccupation, surely ?" "Reasoning as you and I are doing here quietly, at our ease, in this room, no doubt you are right, Mr.Pettifer.But criminals are caught because they don't reason quietly when they have just committed a crime.
The behaviour of a man whose mind is influenced by that condition cannot be explained always by any laws of psychology.

He may be in a wild panic.
He may act as madmen act, or like a child in a rage.

And if my explanation is weak it's no weaker than the only other hypothesis: that Mrs.Ballantyne herself dragged him into the open." Mr.Pettifer shook his head.
"I am not so sure.

I can conceive a condition of horror in the wife, horror at what she had done, which would make that act not merely possible but almost inevitable.

I make no claims to being an imaginative man, Mr.Thresk, but I try to put myself into the position of the wife"; and he described with a vividness for which Thresk was not prepared the scene as he saw it.
"She goes to bed, she undresses and goes to bed--she must do that if she is to escape--she puts out her light, she lies in the dark awake, and under the same roof, close to her, in the dark too, is lying the man she has killed.