Hercule Poirot

‘Ah! Yes? Shall I go and see him now?’
‘Not just yet. He got hardly any sleep last night. In the end I gave him a strong sleeping draught. He is still asleep, and I don’t want to disturb him.’
‘I quite understand. That was very wise. I could see last night that the shock had been very great.’
She said seriously:
‘You see, M. Poirot, he reallycared -much more than the others.’
‘I understand.’
She asked:
‘Have you-has the superintendent-any idea of who can have done this awful thing?’
Poirot said deliberately:
‘We have certain ideas, madame, as to who didnot do it.’
Lydia said, almost impatiently:
‘It’s like a nightmare-so fantastic-I can’t believe it’sreal!’ 
She added:
‘What about Horbury? Was he really at the cinema, as he said?’
‘Yes, madame, his story has been checked. He was speaking the truth.’
Lydia stopped and plucked at a bit of yew. Her face went a little paler. She said:
‘But that’sawful! It only leaves-the family!’
‘Exactly.’
‘M. Poirot, Ican’t believe it!’
‘Madame, youcan and youdo believe it!’
She seemed about to protest. Then suddenly she smiled ruefully.
She said:
‘What a hypocrite one is!’
He nodded.
‘If you were to be frank with me, madame,’ he said, ‘you would admit that to you it seems quite natural that one of his family should murder your father-in-law.’
Lydia said sharply:
‘That’s really a fantastic thing to say, M. Poirot!’
‘Yes, it is. But your father-in-law was a fantastic person!’
Lydia said:
‘Poor old man. I can feel sorry for him now. When he was alive, he just annoyed me unspeakably!’
Poirot said: 
‘So I should imagine!’
He bent over one of the stone sinks.
‘They are very ingenious, these. Very pleasing.’
‘I’m glad you like them. It’s one of my hobbies. Do you like this Arctic one with the penguins and the ice?’
‘Charming. And this-what is this?’
‘Oh, that’s the Dead Sea-or going to be. It isn’t finished yet. You mustn’t look at it. Now this one is supposed to be Piana in Corsica. The rocks there, you know, are quite pink and too lovely where they go down into the blue sea. This desert scene is rather fun, don’t you think?’
She led him along. When they had reached the farther end she glanced at her wrist-watch.
‘I must go and see if Alfred is awake.’
When she had gone Poirot went slowly back again to the garden representing the Dead Sea. He looked at it with a good deal of interest. Then he scooped up a few of the pebbles and let them run through his fingers.
Suddenly his face changed. He held up the pebbles close to his face.
‘Sapristi!’ he said. ‘This is a surprise! Now what exactly does this mean?’