He sprang up the ladder, and Ross bounded aft, somewhat bewildered by the sudden turn of events. He was temporarily at his wits' end. But when Foster floundered down to the deck in a deluge of water from above, and the conning-tower hatch closed with a ringing clang, he understood. One look at the depth indicator was enough. The boat was sinking. He sprang to the sea-cock valve. It was wide open.

"Blast your wretched, black heart and soul," he growled, as he hove the wheel around. "Did you open this valve? Hey, answer me. You did, didn't you? And thought to escape yourself--you coward!"

"Oh, God!" cried Foster, running about distractedly. "We're sinking, and I can't get out."

Ross tightened the valve, and sprang toward him, the murder impulse strong in his soul. In imagination, he felt his fingers on the throat of the other, and every strong muscle of his arms closing more tightly his grip. Then their plight dominated his thoughts; he merely struck out silently, and knocked the photographer down.

"Get up," he commanded, as the prostrate man rolled heavily over on his hands and knees. "Get up, I may need you."

Foster arose, and seated himself on a torpedo amidships, where he sank his head in his hands. With a glance at him, and a reassuring look at the girl, who still remained forward, Ross went aft to connect up the pump. But as he went, he noticed that the deck inclined more and more with each passing moment.

He found the depressed engine room full of water, and the motor flooded.

It was useless to start it; it would short-circuit at the first contact; and he halted, wondering at the boat's being down by the stern so much, until a snapping sound from forward apprised him of the reason.

The painter at the boom had held her nose up until the weight was too much for it, and, with its parting, the little craft assumed nearly an even keel, while the water rushed forward among the battery jars beneath the deck. Then a strong, astringent odor arose through the seams in the deck, and Ross became alive.

"Battery gas!" he exclaimed, as he ran amidships, tumbling Foster off the torpedo with a kick--for he was in his way. He reached up and turned valve after valve, admitting compressed air from the flasks to the filled tanks, to blow out the water. This done, he looked at the depth indicator; it registered seventy feet; but, before he could determine the speed of descent, there came a shock that permeated the whole boat. They were on the bottom.

"And Lord only knows," groaned Ross, "how much we've taken in! But it's only three atmospheres, thank God. Here, you," he commanded to the nerveless Foster, who had again found a seat. "Lend a hand on this pump.

I'll deal with your case when we get up."

"What must I do?" asked Foster, plaintively, as he turned his face, an ashy green now, toward Ross.

"Pump," yelled Ross, in his ear. "Pump till you break your back if necessary. Ship that brake."

He handed Foster his pump-brake, and they shipped them in the hand-pump.

But, heave as they might, they could not move it, except in jerks of about an inch. With an old-fashioned force-pump, rusty from disuse, a three-inch outlet, and three atmospheres of pressure, pumping was useless, and they gave it up, even though the girl added her little weight and strength to the task.

Ross had plenty of compressed air in the numerous air flasks scattered about, and, as he could blow out no more tanks, he expended a jet into the choking atmosphere of the boat. It sweetened the air a little, but there was enough of the powerful, poisonous gas generated to keep them all coughing continually. However, he seated the girl close to the air jet, so that she need not suffer more than was necessary.

"Are we in danger, John?" she asked. "Real danger, I mean?"

"Yes, dear, we are," he answered, tenderly. "And it is best that you should know. I have driven out all the water possible, and we cannot pump at this depth. Higher up we could. But I can eject the torpedo from the tube, and perhaps the others. That will lighten us a good deal."

He went forward, driving Foster before him--for he did not care to leave him too close to the girl--and pushed him bodily into the cramped space between the tube and the trimming tanks.

"Stay there," he said, incisively, "until I want you."

"What can I do?" whimpered the photographer, a brave bully before the girl, when safe; a stricken poltroon now. "I'll do anything you say, to get to the surface."

"You'll get to the surface in time," answered Ross, significantly. "How much do you weigh?"

"Two hundred pounds."

"Two hundred more than we want. However, I'll get rid of this torpedo."

Ross drove the water out of the tube, opened the breech-door; and, reaching in with a long, heavy wire, lifted the starting lever and water tripper that gave motion to the torpedo's engine. The exhaust of air into the tube was driven out into the boat by the rapidly moving screws, and in a few moments the engine ran down.

Then Ross closed the door, flooded the tube, opened the forward door, or port, and sent out the torpedo, confident that, with a dead engine, it would float harmlessly to the surface, and perhaps locate their position to the fleet; for there could be little doubt that the harbor above was dotted with boats, dragging for the sunken submarine.

As the torpedo went out, Ross noticed that the nose of the boat lifted a little, then settled as the tube filled with water. This was encouraging, and he expelled the water. The nose again lifted, but the stern still held to the bottom. There were two other torpedoes, one each side, amidships, and though the dragging to the tube of these heavy weights was a job for all hands, Ross essayed it.

They were mounted on trucks, and with what mechanical aids and purchases he could bring to bear, he and the subdued Foster labored at the task, and in an hour had the starboard torpedo in the tube.

As he was expending weights, he did not take into the 'midship tank an equal weight of water, as was usual to keep the boat in trim, and when the torpedo, robbed of motive power and detonator, went out, the bow lifted still higher, though the stern held, as was evidenced by the grating sound from aft. The tide was drifting the boat along the bottom.

Another hour of hard, perspiring work rid them of the other torpedo, and the boat now inclined at an angle of thirty degrees, down by the stern because of the water in the engine room, but not yet at the critical angle that caused the flooding of the after battery jars as the boat sank.

Ross looked at the depth indicator, but found small comfort. It read off a depth of about sixty feet, but this only meant the lift of the bow.

However, the propeller guard only occasionally struck the bottom now, proving to Ross that, could he expend a very little more weight, the boat would rise to the surface, where, even though he might not pump, his periscope and conning-tower could be seen. He panted after his labors until he had regained breath, then said to Foster:

"You next."

"I next? What do you mean?"

"You want to get to the surface, don't you?" said Ross, grimly. "You expressed yourself as willing to do anything I might say, in order to get to the surface. Well, strip off your coat, vest, and shoes, and crawl into that tube."

"What? To drown? No, I will not."

"Yes, you will. Can you swim?"

"I can swim, but not when I am shot out of a gun."

"Then you'll drown. Peel off."

"I cannot. I cannot. Would you kill me?"

"Don't care much," answered Ross, quietly, "if I do. Only I don't want your dead body in the boat. Come, now," he added, his voice rising. "I'm giving you a chance for your life. I can swim, too, and would not hesitate at going out that tube, if I were sure that the boat, deprived of my weight, would rise. But I am not sure, so I send you, not only because you are heavier than I, but because, as Miss Fleming must remain, I prefer to remain, too, to live or die with her. Understand?"

"But, Miss Fleming," cackled Foster. "She can swim. I've heard her say so."

"You cowardly scoundrel," said Ross, his eyes ablaze with scorn and rage. He had already shed his coat and vest. Now he rolled up his shirt-sleeves. "Will you go into that tube of your own volition, conscious, so that you may take a long breath before I flood the tube, or unconscious, and pushed in like a bag of meal, to drown before you know what ails you--which?"

"No," shrieked Foster, as the menacing face and fists of Ross drew close to him. "I will not. Do something else. You are a sailor. You know what to do. Do something else."

Ross' reply was a crashing blow in the face, that sent Foster reeling toward the tube. But he arose, and returned, the animal fear in him changed to courage. He was a powerfully built man, taller, broader, and heavier than Ross, and what he lacked in skill with his fists, he possessed in the momentum of his lunges, and his utter indifference to pain.

Ross was a trained boxer, strong, and agile, and where he struck the larger man he left his mark; but in the contracted floor space of the submarine he was at a disadvantage. But he fought on, striking, ducking, and dodging--striving not only for his own life, but that of the girl whom he loved, who, seated on the 'midship trimming tank, was watching the fight with pale face and wide-open, frightened eyes.

Once, Ross managed to trip him as he lunged, and Foster fell headlong; but before Ross could secure a weapon or implement to aid him in the unequal combat, he was up and coming back, with nose bleeding and swollen, eyes blackened and half closed, and contusions plentifully sprinkled over his whole face.

He growled incoherently; he was reduced by fear and pain to the level of a beast, and, beast-like, he fought for his life--with hands and feet, only the possession of the prehensile thumb, perhaps, preventing him from using his teeth; for Ross, unable to avoid his next blind lunge, went down, with the whole two hundred pounds of Foster on top of him, and felt the stricture of his clutch on his throat.

A man being choked quickly loses power of volition, entirely distinct from the inhibition coming of suppressed breathing; after a few moments, his movements are involuntary.

Ross, with flashes of light before his eyes, soon took his hands from the iron fingers at his throat, and, with the darkening of his faculties, his arms and legs went through flail-like motions, rising and falling, thumping the deck with rhythmic regularity.

Something in this exhibition must have affected the girl at the air jet; for Ross soon began to breathe convulsively, then to see more or less distinctly--while his limbs ceased their flapping--and the first thing he saw was the girl standing over him, her face white as the whites of her distended eyes, her lips pressed tightly together, and poised aloft in her hands one of the pump-brakes, ready for another descent upon the head of Foster, who, still and inert, lay by the side of Ross.