In another moment he was aware of the dark figure of a man crouched beside him, and then he knew that the light which glittered over his head was the shimmer of the stars against a steel blade.
The knife, as he stared, jerked up and then down with a sweep; Harrigan shot up his hand to meet the blow, and his grip fastened on a wrist.
Wrenching on that wrist, he jerked himself to his knees, and the knife clattered on the deck, but at the same instant the other man--a dim figure which he could barely make out in the thick night--rushed on him, a shoulder struck against his chest, and he was thrown sprawling on the deck, sliding with the toss of the deck underneath the rail.

He would have fallen overboard had he not kept his grip on that wrist, and as he reached the perilous edge, the other man jerked back to free his arm.
He succeeded, but the effort checked the slide of Harrigan's great body, and the next instant the Irishman was on his feet.

He drove at the elusive figure with his balled fist, but the other ducked beneath the blow and fled down the ladder.

Harrigan stopped only long enough to sweep up the fallen knife before he followed, but when he reached the edge of the deck, the waist of the ship extending back to the main cabin was empty.

The man, whoever he was, must have fled into the forecastle.
Harrigan knew that if one of the sailors had dared to attack him, he must be suspected, and if he was suspected by one, that one would poison the minds of a dozen others in a short time.