POSTERN OF FATE Agatha Christie

'Oh,' said Tuppence, 'don't be an idiot.'
'I'm not being an idiot,' Tommy had said. 'I am just being a wise and
careful husband, looking after something which is one of my favourite
possessions. I don't know why it is -'
'Because,' said Tuppence, 'I am so charming, so good-looking, such a
good companion and because I take so much care of you.'
'That also, maybe,' said Tommy, 'but I could give you another list.'
'I don't feel I should like that,' said Tuppence. 'No, I don't think so. I
think you have several saved-up grievances. But don't worry.
Everything will be quite all right. You've only got to come back and call
me when you get in.'
But now where was Tuppence?
'The little devil,' said Tommy. 'She's gone out somewhere.'
He went on into the room upstairs where he had found her before.
Looking at another child's book, he supposed. Getting excited again
about some silly words that a silly child had underlined in red ink. On
the trail of Mary Jordan, whoever she was. Mary Jordan, who hadn't
died a natural death. He couldn't help wondering. A long time ago,
presumably, the people who d had the house and sold it to them had
been named Jones. They hadn't been there very long, only three or
four years. No, this child of the Robert Louis Stevenson book dated
from further back than that. Anyway, Tuppence wasn't here in this