They'll take me away and they'll say I'm guilty of murder. It wasn't murder. I just had to do it. Sometimes I do have to do things. I wanted to see the blood, you know. I couldn't wait to see Molly die, though. I ran away. But I knew she would die. I just hoped you wouldn't find her. She just fell over the cliff.

People would say it was an accident.' " "It's a horrible story," said Desmond.

"Yes," said Celia, "it's a horrible story, but it's better to know. It's better to know, isn't it? I can't even feel sorry for her. I mean for my mother. I know she was sweet. I know there was never any trace of evil in her-she was good all through-and I know, I can understand, why my father didn't want to marry Dolly. He wanted to marry my mother because he loved her and he had found out by then that there was something wrong with Dolly. Something bad and twisted. But how-how did you do it all?" "We told a good many lies," said Zeiie. "We hoped the body would not be found so that later perhaps it might be removed in the night or something like that to somewhere where it could look as though she'd fallen down into the sea. But then we thought of the sleep-walking story. What we had to do was really quite simple. Alistair said, 'It's frightening, you know.

But I promised-I swore to Molly when she was dying. I swore I'd do as she asked. There's a way, a possible way to save Dolly, if only Dolly can do her part. I don't know if she's capable of it.' I said, 'Do what?' And Alistair said, 'Pretend she's Molly and that it's Dorothea who walked in her sleep and fell to her death.' "We managed it. Took Dolly to an empty cottage we knew of and I stayed with her there for some days. Alistair said Molly had been taken to hospital suffering from shock after the discovery that her sister had fallen over the cliff while walking in her sleep at night. Then we brought Dolly back- brought her back as Molly-wearing Molly's clothes and Molly's wig. I got extra wigs-the kind with curls, which really did disguise her. The dear old housekeeper, Janet, couldn't see very well. Dolly and Molly were really very much alike, you know, and their voices were alike. Everyone accepted quite easily that it was Molly, behaving rather peculiarly now and then because of still suffering from shock. It all seemed quite natural. That was the horrible part of it-" "But how could she keep it up?" asked Celia. "It must have been dreadfully difficult." "No-she did not find it difficult. She had got, you see, what she wanted-what she had always wanted. She had got Alistair-" "But Alistair-how could he bear it?" "He told me why and how-on the day he had arranged for me to go back to Switzerland. He told me what I had to do and then he told me what he was going to do.

"He said: "There is only one thing for me to do. I promised Margaret that I wouldn't hand Dolly over to the police, that it should never be known that she was a murderess, that the children were never to know that they had a murderess for an aunt. No one need ever know that Dolly committed murder.

She walked in her sleep and fell over the cliff-a sad accident and she will be buried here in the church, and under her own name.' " 'How can you let that be done?' I asked. I couldn't bear it.

"He said: 'Because of what I am going to do-you have got to know about it.' " 'You see,' he said, 'Dolly has to be stopped from living. If she's near children, she'll take more lives-poor soul; she's not fit to live. But you must understand, Zeiie, that because of what I am going to do, I must pay with my own life, too. I shall live here quietly for a few weeks with Dolly playing the part of my wife-and then there will be another tragedy-' "I didn't understand what he meant. I said, 'Another accident? Sleepwalking again?' And he said, 'No-what will be known to the world is that I and Molly have both committed suicide. I don't suppose the reason will ever be known.

They may think it's because she was convinced she had cancer-or that I thought so-all sorts of things may be suggested. But you see-you must help me, Zeiie. You are the only person who really loves me and loves Molly and loves the children. If Dolly has got to die, I am the only person who must do it. She won't be unhappy or frightened. I shall shoot her and then myself. Her fingerprints will show on the revolver because she handled it not long ago, and mine will be there too. Justice has to be done and I have to be the executioner. The thing I want you to know is that I did-that I still do-love them both. Molly more than my life. Dolly because I pity her so much for what she was born to be.' He said, 'Always remember that-' " Zeiie rose and came towards Celia. "Now you know the truth," she said. "I promised your father that you should never know.

I have broken my word. I never meant to reveal it to you or to anyone else. Monsieur Poirot made me feel differently. But- it's such a horrible story-" "I understand how you felt," said Celia. "Perhaps you were right from your point of view, but I-I am glad to know, because now a great burden seems to have been lifted off me-" "Because now," said Desmond, "we both know. And it's something we'll never mind about knowing. It was a tragedy.

As Monsieur Poirot here has said, it was a real tragedy of two people who loved each other. But they didn't kill each other, because they loved each other. One was murdered and the other executed a murderer for the sake of humanity so that more children shouldn't suffer. One can forgive him if he was wrong, but I don't think it was wrong, really." "She was a frightening woman always," said Celia. "Even when I was a child I was frightened of her, but I didn't know why. But I do know why now. I think my father was a brave man to do what he did. He did what my mother asked him to do, begged him to do with her dying breath. He saved her twin sister, whom I think she'd always loved very dearly. I like to think-oh, it seems a silly thing for me to say-" she looked doubtfully at Hercule Poirot. "Perhaps you won't think so. I expect you're a Catholic, but it's what's written on their tombstone. 'In death they were not divided.' It doesn't mean that they died together, but I think they are together. I think they came together afterwards. Two people who loved each other very much, and my poor aunt whom I'll try to feel more kindly about than I ever did-my poor aunt didn't have to suffer for what she couldn't perhaps help herself doing. Mind you," said Celia, suddenly breaking into her ordinary everyday voice, "she wasn't a nice person. You can't help not liking people if they're not nice people. Perhaps she could have been different if she tried, but perhaps she couldn't. And if so, one has to think of her as someone who was very ill-like somebody, for instance, who had plague in a village and they wouldn't let her go out or feed her and she couldn't go among other people because the whole village would have died. Something like that. But I'll try and be sorry for her. And my mother and father-I don't worry about them any more. They loved each other so much, and loved poor, unhappy, hating Dolly." "I think, Celia," said Desmond, "we'd better get married now as soon as possible. I can tell you one thing. My mother is never going to hear anything about this. She's not my own mother and she's not a person I can trust with this sort of secret." "Your adopted mother, Desmond," said Poirot, "I have good reason to believe was anxious to come between you and Celia and tried to influence you in the idea that from her mother and father she might have inherited some terrible characteristic. But you know, or you may not know and I see no reason why I should not tell you, you will inherit from the woman who was your real mother and who died not very long ago leaving all her money to you. You will inherit a very large sum when you reach the age of twenty-five." "If I marry Celia, of course we shall need the money to live on," said Desmond. "I quite understand, I know my fcresent adopted mother is very keen on money and I often lend her money even now. She suggested my seeing a lawyer th^ other day because she said it was very dangerous now that: I was over twenty-one, not leaving a will behind me. I supp(}se she thought she'd get the money. I had thought of probably leaving nearly all the money to her. But of course now Celia and I are getting married I shall leave it to Celia-and I didn't like the way my mother tried to put me against Celia." "I think your suspicions are entirely correct," said Poirot.