There was a pause. It was broken by Donaldson, who said in his quiet, precise voice:
'Excuse me, but what evidence have you in support of this statement?'
Poirot said quietly:
'The evidence of the nail, the evidence of Miss Arundell's own written words, and finally the evidence of Miss Lawson's eyes.'
Theresa found her voice.
'She says I did it, does she?'
Poirot did not answer except by bending his head a little.
'Well, it's a lie! I had nothing to do with it!'
'You were kneeling on the stairs for quite another reason?'
'I wasn't kneeling on the stairs at all!'
'Be careful, mademoiselle.'
'I wasn't there! I never came out of my room after I went to bed on any evening I was there.'
'Miss Lawson recognized you.'
'It was probably Bella Tanios or one of the maids she saw.'
'She says it was you.'
'She's a damned liar!'
'She recognized your dressing gown and a brooch you wear.'
'A brooch – what brooch?'
'A brooch with your initials.'
'Oh, I know the one! What a circumstantial liar she is!'
'You still deny that it was you she saw?'
'If it's my word against hers -'
'You are a better liar than she is – eh?'
Theresa said calmly:
'That's probably quite true. But in this case I'm speaking the truth. I wasn't preparing a booby trap, or saying my prayers, or picking up gold or silver, or doing anything at all on the stairs.'
'Have you this brooch that was mentioned?'
'Probably. Do you want to see it?'
'If you please, mademoiselle.'
Theresa got up and left the room. There was an awkward silence. Dr Donaldson looked at Poirot much as I imagined he might have looked at an anatomical specimen.
Theresa returned.
'Here it is.'
She almost flung the ornament at Poirot.
It was a large rather showy chromium or stainless steel brooch with T.A. enclosed in a circle. I had to admit that it was large enough and showy enough to be easily seen in Miss Lawson's mirror.
'I never wear it now. I'm tired of it,' said Theresa. ' London 's been flooded with them. Every little skivvy wears one.'
'But it was expensive when you bought it?'
'Oh, yes. They were quite exclusive to begin with.'
'When was that?'
'Last Christmas, I think it was. Yes, about then.'
'Have you ever lent it to any one?'
'No.'
'You had it with you at Littlegreen House?'
'I suppose I did. Yes, I did. I remember.'
'Did you leave it about at all? Was it out of your possession while you were there?'
'No, it wasn't. I wore it on a green jumper, I remember. And I wore the same jumper every day.'
'And at night?'
'It was still in the jumper.'
'And the jumper?'
'Oh, hell, the jumper was sitting on a chair.'
'You are sure no one removed the brooch and put it back again the next day?'
'We'll say so in court if you like – if you think that's the best lie to tell! Actually I'm quite sure that nothing like that happened! It's a pretty idea that somebody framed me – but I don't think it's true.'
Poirot frowned. Then he got up, attached the brooch carefully to his coat lapel and approached a mirror on a table at the other end of the room. He stood in front of it and then moved slowly backward, getting an effect of distance.
Then he uttered a grunt.
'Imbecile that I am! Of course!'
He came back and handed the brooch to Theresa with a bow.
'You are quite right, mademoiselle. The brooch did not leave your possession! I have been regrettably dense.'
'I do like modesty,' said Theresa, pinning the brooch on carelessly.
She looked up at him.
'Anything more? I ought to be going.'
'Nothing that cannot be discussed later.'
Theresa moved towards the door. Poirot went on in a quiet voice:
'There is a question of exhumation, it is true -'
Theresa stopped dead. The brooch fell from her hand to the ground.
'What's that?'
Poirot said clearly:
'It is possible that the body of Miss Emily Arundell may be exhumed.'
Theresa stood still, her hands clenched.
She said in a low, angry voice:
'Is this your doing? It can't be done without an application from the family!'
'You are wrong, mademoiselle. It can be done on an order from the Home Office.'
'My God!' said Theresa.
She turned and walked swiftly up and down.
Donaldson said quietly:
'I really don't see that there is any need to be so upset, Tessa. I dare say that to an outsider the idea is not very pleasant, but -'
She interrupted him.
'Don't be a fool, Rex!'
Poirot asked:
'The idea disturbs you, mademoiselle?'
'Of course it does! It isn't decent. Poor old Aunt Emily. Why the devil should she be exhumed?'
'I presume,' said Donaldson, 'that there is some doubt as to the cause of death?'
He looked inquiringly at Poirot. He went on. 'I confess that I am surprised. I think that there is no doubt that Miss Arundell died a natural death from a disease of long standing.'
'You told me something about a rabbit and liver trouble once,' said Theresa. 'I've forgotten it now, but you infect a rabbit with blood from a person with yellow atrophy of the liver, and then you inject that rabbit's blood into another rabbit, and then that second rabbit's blood into a person and the person gets a diseased liver. Something like that.'
'That was merely an illustration of serum therapeutics,' said Donaldson patiently.
'Pity there are so many rabbits in the story!' said Theresa with a reckless laugh. 'None of us keep rabbits.' She turned on Poirot and her voice altered.
'M. Poirot, is this true?' she asked.
