“Mir Jan!” exclaimed Iris.

“What now?” demanded Jenks over the side.

“Sahib, they come!”

“I am prepared.  Let that snake get back to his hole in the rock, lest a mongoose seize him by the head.”

Mir Jan, engaged in a scouting expedition on his own account, understood that the officer-sahib’s orders must be obeyed.  He vanished.  Soon they heard a great crackling among the bushes on the right, but Jenks knew even before he looked that the Dyaks had correctly estimated the extent of his fire zone and would keep out of it.

The first physical intimation of the enemy’s design they received was a pungent but pleasant smell of burning pine, borne to them by the northerly breeze and filling the air with its aroma.  The Dyaks kindled a huge fire.  The heat was perceptible even on the ledge, but the minutes passed, and the dawn broadened into day without any other result being achieved.

Iris, a little drawn and pale with suspense, said with a timid giggle—­

“This does not seem to be so very serious.  It reminds me of my efforts to cook.”

“There is more to follow, I fear, dear one.  But the Dyaks are fools.  They should have waited until night fell again, after wearing us out by constant vigilance all day.  If they intend to employ smoke it would be far worse for us at night.”

Phew!  A volume of murky vapor arose that nearly suffocated them by the first whiff of its noisome fumes.  It curled like a black pall over the face of the rock and blotted out sea and sky.  They coughed incessantly, and nearly choked, for the Dyaks had thrown wet seaweed on top of the burning pile of dry wood.  Mir Jan, born in interior India, knew little about the sea or its products, and when the savages talked of seaweed he thought they meant green wood.  Fortunately for him, the ascending clouds of smoke missed the cave, or infallibly he must have been stifled.

“Lie flat on the rock!” gasped Jenks.  Careless of waste, he poured water over a coat and made Iris bury her mouth and nose in the wet cloth.  This gave her immediate relief, and she showed her woman’s wit by tying the sleeves of the garment behind her neck.  Jenks nodded comprehension and followed her example, for by this means their hands were left free.

The black cloud grew more dense each few seconds.  Nevertheless, owing to the slope of the ledge, and the tendency of the smoke to rise, the south side was far more tenable than the north.  Quick to note this favorable circumstance, the sailor deduced a further fact from it.  A barrier erected on the extreme right of the ledge would be a material gain.  He sprang up, dragged the huge tarpaulin from its former location, and propped it on the handle of the pickaxe, driven by one mighty stroke deep into a crevice of the rock.

It was no mean feat of strength that he performed.  He swung the heavy and cumbrous canvas into position as if it were a dust cloth.  He emerged from the gloom of the driven cloud red-eyed but triumphant.  Instantly the vapor on the ledge lessened, and they could breathe, even talk.  Overhead and in front the smoke swept in ever-increasing density, but once again the sailor had outwitted the Dyaks’ manoeuvres.