Not a day passed on which Rosa did not come to have her chat with Cornelius.

The tulips, concerning whose cultivation Rosa was taught all the mysteries of the art, formed the principal topic of the conversation; but, interesting as the subject was, people cannot always talk about tulips.

They therefore began to chat also about other things, and the tulip-fancier found out to his great astonishment what a vast range of subjects a conversation may comprise.

Only Rosa had made it a habit to keep her pretty face invariably six inches distant from the grating, having perhaps become distrustful of herself.

There was one thing especially which gave Cornelius almost as much anxiety as his bulbs -- a subject to which he always returned -- the dependence of Rosa on her father.

Indeed, Van Baerle's happiness depended on the whim of this man. He might one day find Loewestein dull, or the air of the place unhealthy, or the gin bad, and leave the fortress, and take his daughter with him, when Cornelius and Rosa would again be separated.

"Of what use would the carrier pigeons then be?" said Cornelius to Rosa, "as you, my dear girl, would not be able to read what I should write to you, nor to write to me your thoughts in return."

"Well," answered Rosa, who in her heart heart was as much afraid of a separation as Cornelius himself, "we have one hour every evening, let us make good use of it."

"I don't think we make such a bad use of it as it is."

"Let us employ it even better," said Rosa, smiling. "Teach me to read and write. I shall make the best of your lessons, believe me; and, in this way, we shall never be separated any more, except by our own will."

"Oh, then, we have an eternity before us," said Cornelius.

Rosa smiled, and quietly shrugged her shoulders.

"Will you remain for ever in prison?" she said, "and after having granted you your life, will not his Highness also grant you your liberty? And will you not then recover your fortune, and be a rich man, and then, when you are driving in your own coach, riding your own horse, will you still look at poor Rosa, the daughter of a jailer, scarcely better than a hangman?"

Cornelius tried to contradict her, and certainly he would have done so with all his heart, and with all the sincerity of a soul full of love.

She, however, smilingly interrupted him, saying, "How is your tulip going on?"

To speak to Cornelius of his tulip was an expedient resorted to by her to make him forget everything, even Rosa herself.

"Very well, indeed," he said, "the coat is growing black, the sprouting has commenced, the veins of the bulb are swelling, in eight days hence, and perhaps sooner, we may distinguish the first buds of the leaves protruding. And yours Rosa?"

"Oh, I have done things on a large scale, and according to your directions."

"Now, let me hear, Rosa, what you have done," said Cornelius, with as tender an anxiety as he had lately shown to herself.

"Well," she said, smiling, for in her own heart she could not help studying this double love of the prisoner for herself and for the black tulip, "I have done things on a large scale; I have prepared a bed as you described it to me, on a clear spot, far from trees and walls, in a soil slightly mixed with sand, rather moist than dry without a fragment of stone or pebble."

“Yes, it was by their light, and that of the lady’s bedroom candle, that the burglars saw their way about.”

“And what did they take?”

“Well, they did not take much — only half a dozen articles of plate off the sideboard. Lady Brackenstall thinks that they were themselves so disturbed by the death of Sir Eustace that they did not ransack the house, as they would otherwise have done.”

“No doubt that is true, and yet they drank some wine, I understand.”

“To steady their nerves.”

“Exactly. These three glasses upon the sideboard have been untouched, I suppose?”

“Yes, and the bottle stands as they left it.”

“Let us look at it. Halloa, halloa! What is this?”

The three glasses were grouped together, all of them tinged with wine, and one of them containing some dregs of beeswing. The bottle stood near them, two-thirds full, and beside it lay a long, deeply stained cork. Its appearance and the dust upon the bottle showed that it was no common vintage which the murderers had enjoyed.

A change had come over Holmes’s manner. He had lost his listless expression, and again I saw an alert light of interest in his keen, deep-set eyes. He raised the cork and examined it minutely.

“How did they draw it?” he asked.

Hopkins pointed to a half-opened drawer. In it lay some table linen and a large corkscrew.

“Did Lady Brackenstall say that screw was used?”

“No, you remember that she was senseless at the moment when the bottle was opened.”

“Quite so. As a matter of fact, that screw was not used. This bottle was opened by a pocket screw, probably contained in a knife, and not more than an inch and a half long. If you will examine the top of the cork, you will observe that the screw was driven in three times before the cork was extracted. It has never been transfixed. This long screw would have transfixed it and drawn it up with a single pull. When you catch this fellow, you will find that he has one of these multiplex knives in his possession.”

“Excellent!” said Hopkins.

“But these glasses do puzzle me, I confess. Lady Brackenstall actually saw the three men drinking, did she not?”

“Yes; she was clear about that.”

“Then there is an end of it. What more is to be said? And yet, you must admit, that the three glasses are very remarkable, Hopkins. What? You see nothing remarkable? Well, well, let it pass. Perhaps, when a man has special knowledge and special powers like my own, it rather encourages him to seek a complex explanation when a simpler one is at hand. Of course, it must be a mere chance about the glasses. Well, good-morning, Hopkins. I don’t see that I can be of any use to you, and you appear to have your case very clear. You will let me know when Randall is arrested, and any further developments which may occur. I trust that I shall soon have to congratulate you upon a successful conclusion. Come, Watson, I fancy that we may employ ourselves more profitably at home.”