In response, Cinderella took from her bag an object wrapped up in paper, and handed it silently to Poirot. The latter unwrapped it. I gave a start-for it was the aeroplane dagger which I understood she had cast into the sea. Strange, how reluctant women always are to destroy the most compromising of objects and documents!

'Tres bien, mon enfant,' said Poirot. 'I am pleased with you. Go now and rest yourself. Hastings here and I have work to do. You shall see him tomorrow.'

'Where are you going?' asked the girl, her eyes widening.

'You shall hear all about it tomorrow.'

'Because wherever you're going, I'm coming too.'

'But, mademoiselle-'

'I'm coming too, I tell you.'

Poirot realized that it was futile to argue. He gave in. 'Come then, mademoiselle. But it will not be amusing. In all probability nothing will happen.'

The girl made no reply.

Twenty minutes later we set forth. It was quite dark now, a close oppressive evening. Poirot led the way out of the town in the direction of the Villa Genevieve. But when he reached the Villa Marguerite he paused.

'I should like to assure myself that all goes well with Jack Renauld. Come with me, Hastings. Mademoiselle will perhaps remain outside. Madame Daubreuil might say something which would wound her.'

We unlatched the gate, and walked up the path. As we went round to the side of the house, I drew Poirot's attention to a window on the first floor. Thrown sharply on the blind was the profile of Marthe Daubreuil.

'Ah!' said Poirot. 'I figure to myself that that is the room where we shall find Jack Renauld.'

Madame Daubreuil opened the door to us. She explained that Jack was much the same but perhaps we would like to see for ourselves. She led us upstairs and into the bedroom.

Marthe Daubreuil was sitting by a table with a lamp on it, working. She put her finger to her lips as we entered.

Jack Renauld was sleeping an uneasy, fitful sleep, his head turning from side to side and his face still unduly flushed.

'Is the doctor coming again?' asked Poirot in a whisper.

'Not unless we send. He is sleeping-that is the great thing. Maman made him a tisane.'

She sat down again with her embroidery as we left the room. Madame Daubreuil accompanied us down the stairs.

Since I had learned of her past history, I viewed this woman with increased interest. She stood there with her eyes cast down, the same very faint, enigmatical smile that I remembered on her lips. And suddenly I felt afraid of her, as one might feel afraid of a beautiful poisonous snake.

'I hope we have not deranged you, madame,' said Poirot politely, as she opened the door for us to pass out.

'Not at all, monsieur.'

'By the way,' said Poirot, as though struck by an afterthought, 'Monsieur Stonor has not been in Merlinville today, has he?'

I could not at all fathom the point of this question, which I well knew to be meaningless as far as Poirot was concerned.

Madame Daubreuil replied quite composedly: 'Not that I know of.'

'He has not had an interview with Madame Renauld?'

'How should I know that, monsieur?'

'True,' said Poirot. 'I thought you might have seen him coming or going, that is all. Goodnight, madame.'

'Why-' I began.

'No whys, Hastings. There will be time for that later.'

We rejoined Cinderella and made our way rapidly in the direction of the Villa Genevieve. Poirot looked over his shoulder once at the lighted window and the profile of Marthe as she bent over her work.

'He is being guarded at all events,' he muttered.

Arrived at the Villa Genevieve, Poirot took up his stand behind some bushes to the left of the drive, where, while enjoying a good view ourselves, we were completely hidden from sight. The villa itself was in total darkness, everybody was without doubt in bed and asleep. We were almost immediately under the window of Mrs. Renauld's bedroom, which window, I noticed, was open. It seemed to me that it was upon this spot that Poirot's eyes were fixed.

'What are we going to do?' I whispered.

'Watch.'

'But-'

'I do not expect anything to happen for at least an hour, probably two hours, but the-'

His words were interrupted by a long, thin drawn cry: 'Help!'

A light flashed up in the first floor room on the right-hand side of the front door. The cry came from there. And even as we watched there came a shadow on the blind as of two people struggling.

'Mille tonnerres,' cried Poirot. 'She must have changed her room.'

Dashing forward, he battered wildly on the front door.

Then rushing to the tree in the flowerbed, he swarmed up it with the agility of a cat. I followed him, as with a bound he sprang in through the open window. Looking over my shoulder, I saw Dulcie reaching the branch behind me.

'Take care,' I exclaimed.

'Take care of your grandmother!' retorted the girl. 'This is child's play to me.'

Poirot had rushed through the empty room and was pounding on the door.

'Locked and bolted on the outside,' he growled. 'And it will take time to burst it open.'

The cries for help were getting noticeably fainter. I saw despair in Poirot's eyes. He and I together put our shoulders to the door.

Cinderella's voice, calm and dispassionate, came from the window: 'You'll be too late. I guess I'm the only one who can do anything.'

Before I could move a hand to stop her, she appeared to leap from the window into space. I rushed and looked out. To my horror, I saw her hanging by her hands from the roof, propelling herself along by jerks in the direction of the lighted window.

'Good heavens. She'll be killed,' I cried.

'You forget. She's a professional acrobat, Hastings. It was the providence of the good God that made her insist on coming with us tonight. I only pray that she may be in time. All!'

A cry of absolute terror floated out on to the night, as the girl disappeared through the window and then in Cinderella's clear tones came the words: 'No, you don't! I've got you-and my wrists are just like steel.'

At the same moment the door of our prison was opened cautiously by Francoise. Poirot brushed her aside unceremoniously and rushed down the passage to where the other maids were grouped round the farther door.

'It's locked on the inside, monsieur.'

There was the sound of a heavy fall within. After a moment or two the key turned and the door swung slowly open. Cinderella, very pale, beckoned us in.

'She is safe?' demanded Poirot.

'Yes, I was just in time. She was exhausted.'

Mrs. Renauld was half sitting, half lying on the bed. She was gasping for breath.

'Nearly strangled me,' she murmured painfully.

The girl picked up something from the floor and handed it to Poirot. It was a rolled-up ladder of silk rope, very fine but quite strong.

'A getaway,' said Poirot. 'By the window, while we were battering at the door. Where is-the other?'

The girl stood aside a little and pointed. On the ground lay a figure wrapped in some dark material, a fold of which hid the face.

'Dead?'

She nodded. 'I think so. Head must have struck the marble fender.'

'But who is it?' I cried.

'The murderer of Renauld, Hastings. And the would-be murderer of Madame Renauld.'

Puzzled and uncomprehending, I knelt down, and lifting the fold of cloth, looked into the dead beautiful face of Marthe Daubreuil!