Who, then, could it have been? And where had he concealed himself?
The forward deck-house was the place that naturally suggested itself to them. Led by the captain, the two young adventurers started for the small white structure.
"Whoever you are, my man," exclaimed the captain, as he laid hand on the door and thrust it open, "don't dare to try any monkey tricks with us. We'll stand for no nonsense and are armed."
With these words he pushed open the door. But the place, which was evidently a kind of galley—or cook house—combined with sleeping accommodations of a rough character, was empty. A rusty sea-range with pots and pans still on it stretched along the forward end, and cooking materials stood all about. A big barrel of rolled oats, with the top off, stood half open.
"Hullo!" exclaimed the captain, as he gazed into it, "some one's dipped into this lately."
So much was clear. The contents of the barrel had evidently been disturbed by somebody helping himself; but who?
As he propounded the question to himself, Nat looked up, and almost gave way to a shrill cry of alarm as he did so.
There was a small, square, unglazed window above the stove—apparently put there for ventilation.
In this aperture as he glanced up he had, for the second time, encountered the terrible hairy face gazing in at them. But as his eyes met the bright, shifty orbs the visage vanished, and when the others looked up the window was empty.
It was the work of but one second for Nat to dash out of the cook house. But swift as he was the mysterious eavesdropper was quicker. He must have vanished with the celerity of a Jack-in-the-box, for when Nat gained the deck not a trace of anything unusual was to be seen.