The fernery was a huge glass building on one side of the ballroom, filled with Australian and New Zealand ferns, and having a large fountain in the centre sending up a sparkling jet of water, which fell into the shallow stone basin filled with water lilies and their pure white flowers. At the end was a mimic representation of a mountain torrent, with real water tumbling down real rocks, and here and there in the crannies and crevices grew delicate little ferns, while overhead towered the great fronds of the tree ferns. The roof was a dense mass of greenery, and wire baskets filled with sinuous creepers hung down, with their contents straggling over. Electric lights in green globes were skilfully hidden all round, and a faint aquamarine twilight permeated the whole place, and made it look like a mermaid’s grotto in the depths of the sea. Here and there were delightful nooks, with well-cushioned seats, many of which were occupied by pretty girls and their attendant cavaliers. On one side of the fernery a wide door opened on to a low terrace, from whence steps went down to the lawn, and beyond was the dark fringe of trees wherein Pierre was concealed.

Kitty and Vandeloup found a very comfortable nook just opposite the door, and they could see the white gleam of the terrace in the luminous starlight. Every now and then a couple would pass, black silhouettes against the clear sky, and around they could hear the murmur of voices and the musical tinkling of the fountain, while the melancholy music of the valse, with its haunting refrain, sounded through the pale green twilight. Barty Jarper was talking near them, in his mild little way, to a tall young lady in a bilious-looking green dress, and further off Mr Bellthorp was laughing with Mrs Riller behind the friendly shelter of her fan.

‘Well,’ said Vandeloup, amiably, as he sank into a seat beside Kitty, ‘what is this great matter you wish to speak about?’

‘Madame Midas,’ retorted Kitty, looking straight at him.

‘Such a delightful subject,’ murmured Gaston, closing his eyes, as he guessed what was coming; ‘go on, I’m all attention.’

‘You are going to marry her,’ said Miss Marchurst, bending towards him and closing her fan with a snap.

Vandeloup smiled faintly.

‘You don’t say so?’ he murmured, opening his eyes and looking at her lazily; ‘who told you this news—for news it is to me, I assure you?’

‘Then it’s not true?’ added Kitty, eagerly, with a kind of gasp.

‘I’m sure I don’t know,’ he replied, indolently fingering his moustache; ‘I haven’t asked her yet.’

‘You are not going to do so?’ she said, rapidly, with a flush on her face.

‘Why not?’ in surprise; ‘do you object?’

‘Object? my God!’ she ejaculated, in a low fierce tone; ‘have you forgotten what we are to one another?’

‘Friends, I understand,’ he said, looking at his hands, admiringly.

‘And something more,’ she added, bitterly; ‘lovers!’

‘Don’t talk so loud, my dear,’ replied Vandeloup, coolly; ‘it doesn’t do to let everyone know your private business.’

‘It’s private now,’ she said, in a voice of passion, ‘but it will soon be public enough.’

‘Indeed! which paper do you advertise in?’

‘Listen to me, Gaston,’ she said, taking no notice of his sneer; ‘you will never marry Madame Midas; sooner than that, I will reveal all and kill myself.’

‘You forget,’ he said, gently; ‘it is comedy, not tragedy, we play.’

‘That is as I choose,’ she retorted; ‘see!’ and with a sudden gesture she put her hand into the bosom of her dress and took out the bottle of poison with the red bands. ‘I have it still.’

‘So I perceive,’ he answered, smiling. ‘Do you always carry it about with you, like a modern Lucrezia Borgia?’

‘Yes,’ she answered quietly; ‘it never leaves me, you see,’ with a sneer. ‘As you said yourself, it’s always well to be prepared for emergencies.’

‘So it appears,’ observed Vandeloup, with a yawn, sitting up. ‘I wouldn’t use that poison if I were you; it is risky.’

‘Oh, no, it’s not,’ answered Kitty; ‘it is fatal in its results, and leaves no trace behind.’

‘There you are wrong,’ replied Gaston, coolly; ‘it does leave traces behind, but makes it appear as if apoplexy was the cause of death. Give me the bottle?’ peremptorily.

‘No!’ she answered, defiantly, clenching it in her hand.

‘I say yes,’ he said, in an angry whisper; ‘that poison is my secret, and I’m not going to have you play fast and loose with it; give it up,’ and he placed his hand on her wrist.

‘You hurt my wrist,’ she said.

‘I’ll break your wrist, my darling,’ he said, quietly, ‘if you don’t give me that bottle.’

Kitty wrenched her hand away, and rose to her feet.

‘Sooner than that, I’ll throw it away,’ she said, and before he could stop her, she flung the bottle out on to the lawn, where it fell down near the trees.

‘Bah! I will find it,’ he said, springing to his feet, but Kitty was too quick for him.

‘M. Vandeloup,’ she said aloud, so that everyone could hear; ‘kindly take me back to the ball-room, will you, to finish our valse.’

Vandeloup would have refused, but she had his arm, and as everyone was looking at him, he could not refuse without being guilty of marked discourtesy. Kitty had beaten him with his own weapons, so, with a half-admiring glance at her, he took her back to the ball-room, where the waltz was just ending.

‘At all events,’ he said in her ear, as they went smoothly gliding round the room, ‘you won’t be able to do any mischief with it now to yourself or to anyone else.’

‘Won’t I?’ she retorted quickly; ‘I have some more at home.’

‘The deuce!’ he ejaculated.

‘Yes,’ she replied, triumphantly; ‘the bottle I got that belonged to you, I put half its contents into another. So you see I can still do mischief, and,’ in a fierce whisper, ‘I will, if you don’t give up this idea of marrying Madame Midas.’

‘I thought you knew me better than that,’ he said, in a tone of concentrated passion. ‘I will not.’

Then I’ll poison her,’ she retorted.

‘What, the woman who has been so kind to you?’

‘Yes, I’d rather see her dead than married to a devil like you.’

‘How amiable you are, Bebe,’ he said, with a laugh, as the music stopped.

‘I am what you have made me,’ she replied, bitterly, and they walked into the drawing-room.

After this Vandeloup clearly saw that it was a case of diamond cut diamond, for Kitty was becoming as clever with her tongue as he was. After all, though she was his pupil, and was getting as hardened and cynical as possible, he did not think it fair she should use his own weapons against himself. He did not believe she would try and poison Madame Midas, even though she was certain of not being detected, for he thought she was too tender-hearted. But, alas! he had taught her excellently well, and Kitty was rapidly arriving at the conclusion he had long since come to, that number one was the greatest number. Besides, her love for Vandeloup, though not so ardent as it had been, was too intense for her to let any other woman get a hold of him. Altogether, M. Vandeloup was in an extremely unpleasant position, and one of his own making.

Having given Kitty over to the tender care of Mrs Rolleston, Vandeloup hurried outside to look for the missing bottle. He had guessed the position it fell in, and, striking a match, went to look over the smooth close-shorn turf. But though he was a long time, and looked carefully, the bottle was gone.

‘The devil!’ said Vandeloup, startled by this discovery. ‘Who could have picked it up?’

He went back into the conservatory, and, sitting down in his old place, commenced to review the position.

It was most annoying about the poison, there was no doubt of that. He only hoped that whoever picked it up would know nothing about its dangerous qualities. After all, he could be certain about that, as no one but himself knew what the poison was and how it could be used. The person who picked up the bottle would probably throw it away again as useless; and then, again, perhaps when Kitty threw the bottle away the stopper came out, and the contents would be lost. And then Kitty still had more left, but—bah!—she would not use it on Madame Midas. That was the vague threat of a jealous woman to frighten him. The real danger he was in lay in the fact that she might tell Madame Midas the relations between them, and then there would be no chance of his marrying at all. If he could only stop Kitty’s mouth in some way—persuasion was thrown away on her. If he could with safety get rid of her he would. Ah! that was an idea. He had some of this poison—if he could only manage to give it to her, and thus remove her from his path. There would be no risk of discovery, as the poison left no traces behind, and if it came to the worst, it would appear she had committed suicide, for poison similar to what she had used would be found in her possession. It was a pity to kill her, so young and pretty, and yet his safety demanded it; for if she told Madame Midas all, it might lead to further inquiries, and M. Vandeloup well knew his past life would not bear looking into. Another thing, she had threatened him about some secret she held—he did not know what it was, and yet almost guessed; if that was the secret she must be got rid of, for it would imperil not only his liberty, but his life. Well, if he had to get rid of her, the sooner he did so the better, for even on the next day she might tell all—he would have to give her the poison that night—but how? that was the difficulty. He could not do it at this ball, as it would be too apparent if she died—no—it would have to be administered secretly when she went home. But then she would go to Madame Midas’ room to see how she was, and then would retire to her own room. He knew where that was—just off Mrs Villiers’ room; there were French windows in both rooms—two in Mrs Villiers’, and one in Kitty’s. That was the plan—they would be left open as the night was hot. Suppose he went down to St Kilda, and got into the garden, he knew every inch of the way; then he could slip into the open window, and if it was not open, he could use a diamond ring to cut the glass. He had a diamond ring he never wore, so if Kitty was discovered to be poisoned, and the glass cut, they would never suspect him, as he did not wear rings at all, and the evidence of the cut window would show a diamond must have been used. Well, suppose he got inside, Kitty would be asleep, and he could put the poison into the water carafe, or he could put it in a glass of water and leave it standing; the risk would be, would she drink it or not—he would have to run that risk; if he failed this time, he would not the next. But, then, suppose she awoke and screamed—pshaw! when she saw it was he Kitty would not dare to make a scene, and he could easily make some excuse for his presence there. It was a wild scheme, but then he was in such a dangerous position that he had to try everything.

When M. Vandeloup had come to this conclusion he arose, and, going to the supper room, drank a glass of brandy; for even he, cool as he was, felt a little nervous over the crime he was about to commit. He thought he would give Kitty one last chance, so when she was already cloaked, waiting with Mrs Riller for the carriage, he drew her aside.

‘You did not mean what you said tonight,’ he whispered, looking searchingly at her.

‘Yes, I did,’ she replied, defiantly; ‘if you push me to extremities, you must take the consequences.’

‘It will be the worse for you,’ he said, threateningly, as the carriage drove up.

‘I’m not afraid of you,’ she retorted, shrugging her shoulders, a trick she had learned from him; ‘you have ruined my life, but I’m not going to let you ruin Madame’s. I’d sooner see her dead than in your arms.’

‘Remember, I have warned you,’ he said, gravely, handing her to the carriage. ‘Good night!’

‘Good night!’ she answered, mockingly; ‘and to-morrow,’ in a low voice, ‘you will be astonished.’

‘And to-morrow,’ he said to himself, as the carriage drove off, ‘you will be dead.’