At that moment he was somewhat paler than by nature; he wore a heavy frown; and his lips worked, and he looked sharply round him as he walked, like a man besieged with apprehensions. And yet I thought he had a look of triumph underlying all, as though he had already done much, and was near the end of an achievement. Partly from a scruple of delicacy--which I dare say came too late--partly from the pleasure of startling an acquaintance, I desired to make my presence known to him without delay. I got suddenly to my feet, and stepped forward. "Northmour!" said I. I have never had so shocking a surprise in all my days. He leaped on me without a word; something shone in his hand; and he struck for my heart with a dagger. At the same moment I knocked him head over heels. Whether it was my quickness, or his own uncertainty, I know not; but the blade only grazed my shoulder, while the hilt and his fist struck me violently on the mouth. I fled, but not far. I had often and often observed the capabilities of the sand hills for protracted ambush or stealthy advances and retreats; and, not ten yards from the scene of the scuffle, plumped down again upon the grass. The lantern had fallen and gone out. But what was my astonishment to see Northmour slip at a bound into the pavilion, and hear him bar the door behind him with a clang of iron! He had not pursued me. He had run away. Northmour, whom I knew for the most implacable and daring of men, had run away! I could scarce believe my reason; and yet in this strange business, where all was incredible, there was nothing to make a work about in an incredibility more or less. For why was the pavilion secretly prepared? Why had Northmour landed with his guests at dead of night, in half a gale of wind, and with the floe scarce covered? Why had he sought to kill me? Had he not recognized my voice? I wondered. And, above all, how had he come to have a dagger ready in his hand? A dagger, or even a sharp knife, seemed out of keeping with the age in which we lived; and a gentleman landing from his yacht on the shore of his own estate, even although it was at night and with some mysterious circumstances, does not usually, as a matter of fact, walk thus prepared for deadly onslaught. The more I reflected, the further I felt at sea. I recapitulated the elements of mystery, counting them on my fingers: the pavilion secretly prepared for guests; the guests landed at the risk of their lives and to the imminent peril of the yacht; the guests, or at least one of them, in undisguised and seemingly causeless terror; Northmour with a naked weapon; Northmour stabbing his most intimate acquaintance at a word; last, and not least strange, Northmour fleeing from the man whom he had sought to murder, and barricading himself, like a hunted creature, behind the door of the pavilion. Here were at least six separate causes for extreme surprise; each part and parcel with the others, and forming all together one consistent story.