A shaded walk, with a glimpse of sea beyond, embowering trees, a stretch of lawn on one side, and on the other the dormer windows of a fine old house half hidden by scaffolding, from which there came now and then the quick strokes of a workman’s hammer.

It was half-past four, if the sharp little note of a cuckoo-clock, snapping out one, told the time correctly.

Two men are pacing this leafy retreat, both of whom we have seen before, but under circumstances so distracting that we took little note of their appearance, fine as it undoubtedly was in either case. However, we are more at leisure now, and will pause for an instant to give you some idea of these two prominent men, with one of whom our story will henceforth have very much to do.

One of them — the Curator of our famous museum — lacks comeliness of figure, though at moments he can be very impressive. We can therefore recognize him at a distance by means of a certain ungainliness of stride sometimes seen in a man wholly given over to intellectual pursuits. But when he turns and you get a glimpse of his face, you experience at once the scope of mind and charm of spirit which make his countenance a marked one in the metropolis. A little gray about the temples, a tendency — growing upon him, alas!— to raise his hand to his ear when called upon to listen, show that he has already passed the meridian of life; but in his quick glance, and clear and rapid speech, youth still lingers, making of him a companion delightful to many and admirable to all.

The other — Carleton Roberts, his bosom friend, and the museum’s chief director — is of a different type, but no less striking to the eye. For him, personality has done much toward raising him to his present status among the leading men of New York. While not tall, he is tall enough never to look short, owing to the trim elegance of his figure and the quiet dignity of his carriage. He does not need to turn his face to impress you with the idea that he is handsome; but when he does so, you find that your expectations are more than met by the reality. For though he may not have the strictly regular features we naturally associate with one of his poise and matchless outline, there is enough of that quality, and more than enough of that additional elusive something which is an attraction in itself, to make for handsomeness in a marked degree. He, like his friend, has passed his fortieth year, but nowhere save in his abundant locks can one see any sign of approaching age. They are quite white — cut close, but quite white, so white they attracted the notice of his companion, who stole more than one look at them as he chatted on in what had become almost a monologue, so little did Roberts join in the conversation.

Finally the Curator paused, and stealing another look at that white head, remarked anxiously:

“Have you not grown gray very suddenly? I don’t remember your being whiter than myself the day I dined with you just preceding the horrible occurrence at the museum.”

“I have been growing gray for a year,” rejoined the other. “My father was white at forty; I am just forty-three.”

“It becomes you, and yet — Roberts, you have taken this matter too much to heart. We were not to blame in any way, unless it was in having such deadly weapons within reach. How could one suppose ——”

“Yes, how could one suppose!” echoed the director. “And the mystery of it! The police seem no nearer solving the problem now than on the night they practised archery in the galleries. It does wear on me, possibly because I live so much alone. I see ——”

Here he stopped abruptly. They had been strolling in the direction of the house............