It was into a stricken silence that Appleby next spoke.
‘Listen, please,’ he said – and set going the tape-recorder. It was three or four minutes before he switched it off. ‘A very ordinary conversation, wouldn’t you say? It even has a little of what Charles and Grace confessed to us: that they liked a mild gossip about their guests. But what are we to suppose? We are to suppose that Charles certainly recorded it because he knew his wife would die soon. But it was with a very different purpose from the simple commemorative one which Mr Angrave was suggesting to us. Briefly, he was no longer able to bear the spectacle of her suffering, and he decided that he must kill her. A mercy killing is what the newspapers call it.
‘But he didn’t intend that this miserable thing should ever be known. He determined that Grace should meet the appearance of accidental death – death by drowning – and that he himself, for greater security, should own an alibi. So he recorded this talk – in the belvedere, no doubt. Yesterday afternoon – overheard by Friary, as it happened – he tested it out there. And then he was ready.
‘Yesterday evening he and Grace made their little expedition together. On the way to the belvedere he drowned her in the pond. It was just like that.’ Appleby was silent for a moment, ‘And what then? His plan depended on the celebrated punctuality of Friary. He went on to the belvedere, and waited for Friary to pass. As soon as Friary approached, Martineau was going to switch on the tape-recorder. Then, when he was sure that Friary had heard it, he was going to switch it off, and at once join Friary. He was going to see to it that Friary didn’t take a path past the pond, and he was going to remain within sight of one person or another until his wife’s body had been found. But, as it happened, his plan didn’t work.’
Diana Page was weeping again, but this time nobody attended to her. Mrs Gillingham’s sense of the importance of the forms didn’t prevent her from looking like a woman who knows that she is in the presence of guilt and misery. Bobby Angrave and Martine Rivière had scarcely taken their eyes off each other since Appleby began his recital. But now Bobby looked across the room.
‘What do you mean,’ he asked, ‘by saying that the plan didn’t work?’
‘Remember the extraordinary mischance of the fuse. The tape-recorder failed to function, and Friary, as a consequence, walked past a belvedere from which there came nothing but silence. We may imagine that by this time Charles Martineau knew that he had behaved like a madman, and we may take a guess that he simply wandered about. When young Neil came with the news of Mrs Martineau’s death, some instinct of self-preservation made him – for a few futile minutes – play a part. He went into his office and summoned Dr Fell. Then he took out that revolver and killed himself. Perhaps he had meant to do that all along.’
There was a deep silence. Diana, becoming aware of the sound of her own sobs, was frightened into silence too.
‘All that,’ Appleby said, ‘is what we are asked to suppose.’
‘You mean it isn’t the truth?’ Martine demanded.
‘Of course not. Charles could not conceivably have thrust his wife into a pond and drowned her. Such a notion is nothing but a morbid fantasy. Yet a good deal has been built upon it.’
‘You mean that nothing of all this was ever so much as in my uncle’s head?’
‘Virtually that, Martine, I am glad to say. And yet it began with your uncle – and not wholly without a touch of the fantastic. It began too, with this machine. Indeed, I am now going to play you another tape.’ Appleby busied himself with the tape-recorder. ‘This one didn’t have to be home-made. It can be obtained from some educational supplier or other. It’s wonderful what children are taught nowadays. This tape, by the way, wasn’t in the belvedere. It was found by some of Colonel Morrison’s men in a place where I told them to hunt for it. It was in its cardboard box, which has proved useful for fingerprints. It would never have occurred to me to hunt for it, incidentally, but for a fellow called Christopher Sly.’
‘Christopher Sly?’ Martine repeated.
‘A tinker. I’ll explain in a moment. Now listen, please.’
The tape-recorder once more gave its little preliminary hum. And then, with an effect which might have startled the ears even of Holman Hunt’s shadows on the walls, the music room at Charne was overflowing with the song of a nightingale.