I felt Holmes’s hand steal into mine and give me a reassuring shake, as if to say that the situation was within his powers, and that he was easy in his mind. I was not sure whether he had seen what was only too obvious from my position, that the door of the safe was imperfectly closed, and that Milverton might at any moment observe it. In my own mind I had determined that if I were sure, from the rigidity of his gaze, that it had caught his eye, I would at once spring out, throw my great coat over his head, pinion him, and leave the rest to Holmes. But Milverton never looked up. He was languidly interested by the papers in his hand, and page after page was turned as he followed the argument of the lawyer. At least, I thought, when he has finished the document and the cigar he will go to his room, but before he had reached the end of either, there came a remarkable development which turned our thoughts into quite another channel.

Several times I had observed that Milverton looked at his watch, and once he had risen and sat down again, with a gesture of impatience. The idea, however, that he might have an appointment at so strange an hour never occurred to me until a faint sound reached my my ears from the veranda outside. Milverton dropped his papers and sat rigid in his chair. The sound was repeated, and then there came a gentle tap at the door. Milverton rose and opened it.

“Well,” said he, curtly, “you are nearly half an hour late.”

So this was the explanation of the unlocked door and of the nocturnal vigil of Milverton. There was the gentle rustle of a woman’s dress. I had closed the slit between the curtains as Milverton’s face had turned in our direction, but now I ventured very carefully to open it once more. He had resumed his seat, the cigar still projecting at an insolent angle from the corner of his mouth. In front of him, in the full glare of the electric light, there stood a tall, slim, dark woman, a veil over her face, a mantle drawn round her chin. Her breath came quick and fast, and every inch of the lithe figure was quivering with strong emotion.

“Well,” said Milverton, “you made me lose a good night’s rest, my dear. I hope you’ll prove worth it. You couldn’t come any other time — eh?”

The woman shook her head.

“Well, if you couldn’t you couldn’t. If the Countess is a hard mistress, you have your chance to get level with her now. Bless the girl, what are you shivering about? That’s right. Pull yourself together. Now, let us get down to business.” He took a notebook from the drawer of his desk. “You say that you have five letters which compromise the Countess d’Albert. You want to sell them. I want to buy them. So far so good. It only remains to fix a price. I should want to inspect the letters, of course. If they are really good specimens — Great heavens, is it you?”

The woman, without a word, had raised her veil and dropped the mantle from her chin. It was a dark, handsome, clear-cut face which confronted Milverton — a face with a curved nose, strong, dark eyebrows shading hard, glittering eyes, and a straight, thin-lipped mouth set in a dangerous smile.

Rosa watched the flower-pot with an interest which betrayed to Boxtel the real value of the object enclosed in it.

This object could not be anything else but the second bulb, that is to say, the quintessence of all the hopes of the prisoner.

When the nights threatened to be too cold, Rosa took in the flower-pot.

Well, it was then quite evident she was following the instructions of Cornelius, who was afraid of the bulb being killed by frost.

When the sun became too hot, Rosa likewise took in the pot from eleven in the morning until two in the afternoon.

Another proof: Cornelius was afraid lest the soil should become too dry.

But when the first leaves peeped out of the earth Boxtel was fully convinced; and his telescope left him no longer in any uncertainty before they had grown one inch in height.

Cornelius possessed two bulbs, and the second was intrusted to the love and care of Rosa.

For it may well be imagined that the tender secret of the two lovers had not escaped the prying curiosity of Boxtel.

The question, therefore, was how to wrest the second bulb from the care of Rosa.

Certainly this was no easy task.

Rosa watched over her tulip as a mother over her child, or a dove over her eggs.

Rosa never left her room during the day, and, more than that, strange to say, she never left it in the evening.

For seven days Boxtel in vain watched Rosa; she was always at her post.

This happened during those seven days which made Cornelius so unhappy, depriving him at the same time of all news of Rosa and of his tulip.

Would the coolness between Rosa and Cornelius last for ever?

This would have made the theft much more difficult than Mynheer Isaac had at first expected.

We say the theft, for Isaac had simply made up his mind to steal the tulip; and as it grew in the most profound secrecy, and as, moreover, his word, being that of a renowned tulip-grower, would any day be taken against that of an unknown girl without any knowledge of horticulture, or against that of a prisoner convicted of high treason, he confidently hoped that, having once got possession of the bulb, he would be certain to obtain the prize; and then the tulip, instead of being called Tulipa nigra Barlaensis, would go down to posterity under the name of Tulipa nigra Boxtellensis or Boxtellea.

Mynheer Isaac had not yet quite decided which of these two names he would give to the tulip, but, as both meant the same thing, this was, after all, not the important point.

The point was to steal the tulip. But in order that Boxtel might steal the tulip, it was necessary that Rosa should leave her room.

Great therefore was his joy when he saw the usual evening meetings of the lovers resumed.

He first of all took advantage of Rosa's absence to make himself fully acquainted with all the peculiarities of the door of her chamber. The lock was a double one and in good order, but Rosa always took the key with her.

Boxtel at first entertained an idea of stealing the key, but it soon occurred to him, not only that it would be exceedingly difficult to abstract it from her pocket, but also that, when she perceived her loss, she would not leave her room until the lock was changed, and then Boxtel's first theft would be useless.