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 a faint sound reached 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.

Boxtel heard him give the order, and saw the sentry-box put up that very day; but he deemed himself lucky in not having been suspected, and, being more than ever incensed against the successful horticulturist, he resolved to bide his time.

Just then the Tulip Society of Haarlem offered a prize for the discovery (we dare not say the manufacture) of a large black tulip without a spot of colour, a thing which had not yet been accomplished, and was considered impossible, as at that time there did not exist a flower of that species approaching even to a dark nut brown. It was, therefore, generally said that the founders of the prize might just as well have offered two millions as a hundred thousand guilders, since no one would be able to gain it.

The tulip-growing world, however, was thrown by it into a state of most active commotion. Some fanciers caught at the idea without believing it practicable, but such is the power of imagination among florists, that although considering the undertaking as certain to fail, all their thoughts were engrossed by that great black tulip, which was looked upon to be as chimerical as the black swan of Horace or the white raven of French tradition.

Van Baerle was one of the tulip-growers who were struck with the idea; Boxtel thought of it in the light of a speculation. Van Baerle, as soon as the idea had once taken root in his clear and ingenious mind, began slowly the necessary planting and cross-breeding to reduce the tulips which he had grown already from red to brown, and from brown to dark brown.

By the next year he had obtained flowers of a perfect nut-brown, and Boxtel espied them in the border, whereas he had himself as yet only succeeded in producing the light brown.

It might perhaps be interesting to explain to the gentle reader the beautiful chain of theories which go to prove that the tulip borrows its colors from the elements; perhaps we should give him pleasure if we were to maintain and establish that nothing is impossible for a florist who avails himself with judgment and discretion and patience of the sun's heat; the clear water, the juices of the earth, and the cool breezes. But this is not a treatise upon tulips in general; it is the story of one particular tulip which we have undertaken to write, and to that we limit ourselves, however alluring the subject which is so closely allied to ours.

Boxtel, once more worsted by the superiority of his hated rival, was now completely disgusted with tulip-growing, and, being driven half mad, devoted himself entirely to observation.

The house of his rival was quite open to view; a garden exposed to the sun; cabinets with glass walls, shelves, cupboards, boxes, and ticketed pigeon-holes, which could easily be surveyed by the telescope. Boxtel allowed his bulbs to rot in the pits, his seedlings to dry up in their cases, and his tulips to wither in the borders and henceforward occupied himself with nothing else but the doings at Van Baerle's. He breathed through the stalks of Van Baerle's tulips, quenched his thirst with the water he sprinkled upon them, and feasted on the fine soft earth which his neighbour scattered upon his cherished bulbs.