"sheer off!" shouted captain cain, leaning over the bridge-rails and directing the full blast of his powerful voice upon the still unknown craft alongside. "stand clear; we're going full ahead in half a shake."

"hang on a minute, cap'n!" replied broadmayne. "there are only two of us—survivors of the yacht ibex, burnt late last night. if you won't take us on board you might give us some grub and water. we're famished and horribly cold, you know."

captain cain made a brief mental review of the situation, as far as he knew of the facts. he was not a soft-hearted man—far from it. there would be very little risk to the occupants of the boat if they remained adrift for a few hours longer. they were bound to be picked up by some of the up- and down-channel traffic. he could provide them with a few provisions and then go ahead.

on the other hand, he was quite in the dark as to what the two men in the boat had seen or heard. it was much too early for the alerte to reveal her true character, that of a submarine pirate craft. and it was very disconcerting when he, the captain, was congratulating himself that, the alerte had been armed and had gone through additional diving tests under cover of darkness, to find a boat lying alongside with two persons in her who might be remarkably cute in spotting anything out of the ordinary at sea.

the simplest solution was to drop a pig of ballast through the bottom of the boat and leave the two men to their fate. they couldn't keep afloat very long in the open channel in november. on their own admission, they were cold and famished. they'd sink within five minutes.

but the suggestion was dismissed as quickly as it had been formed. captain cain was strongly opposed to taking life wantonly, whether it be man or beast. if occasion arose with sufficient justification for his point of view, the pirate captain would shoot down any one in cold blood or otherwise. again, he had pledged himself to his crew, and for the present it was policy to abide by his plighted word, that he was against performing any violent act against the crews of british ships, and were not these two men british survivors of a disaster?

and, judging by the tone of the man who had spoken, one of the survivors was some one of good, possibly high birth. in any case, the pair might prove useful additional hands to the alerte's complement. if they wouldn't, well he'd make them. there was also the chance that the distressed mariners might be people of social standing and wealth. then there would be a good opportunity to demand ransom. coming on top of the chamfer incident, captain cain decided such a possibility seemed no probability. he would be lucky, indeed, if he could repeat his previous success in that direction.

all this flashed through the ready brain of the pirate captain in a very few seconds. quickly he made up his mind.

"come aboard!" he said briefly.

one of the hands caught the dinghy's painter. a rope ladder was lowered down the perpendicular side of the alerte, and with a final effort to control their cramped limbs, vyse and broadmayne contrived to reach the deck of the pirate submarine.

"take them below!" ordered captain cain from the height of the bridge. "tell davis to serve them with a good hot meal. they can berth for'ard."

with his head swimming and his knees giving way under him, rollo vyse was glad to have the assistance of a couple of the crew to take him below. broadmayne, although feeling decidedly groggy, still retained sufficient alertness of mind to take stock of his immediate surroundings as far as the first streaks of red dawn permitted.

the steel deck littered with kelp and seaweed was in itself suspicious, unless the vessel were a trawler and had just emptied her nets on deck. but there was not the peculiar smell that steam trawlers cannot get away from.

directly the sub found himself below, he knew.

"by jove!" he soliloquised. "she's a sub marine."

in spite of his hunger and fatigue, broadmayne puzzled his brains over the strange situation. what was a submarine, disguised as a surface ship, doing in the channel? her officers and crew were not in naval uniform, although several of them had unmistakable indications of having served under the white ensign. the owner, especially, had the cut of a pukka naval man.

"perhaps she's a new type of q-ship," he thought. "if the manoeuvres were on, i could understand it. won't it be a joke if she is a mystery ship; and won't the owner feel a bit sick when he finds he's harbouring an inquisitive sub on board his hooker? like his confounded cheek, though, making us mess and berth for'ard."

soon the two chums were sitting down to a hot, substantial meal. they were not alone. the crew's quarters in which they were sheltering was occupied by the best part of the watch below, about a dozen rather smart and alert men, older than the usual run of naval ratings. the sub noticed that, without exception, they looked a bit tired and fatigued, consequently he was not surprised to find that his attempts to broach a conversation were resolutely, yet politely, rebuffed. foiled in that direction, broadmayne tried to pick up the threads of the scanty scraps of conversation. again he was foiled. every sentence he overheard had no bearing upon life on board. "shop" in the crew's quarter seemed to be taboo.

he glanced at vyse. rollo, having made a good meal, was leaning back on the settee with his eyes closed. the problem offered no difficulties to the owner of the burnt-out ibex, for the simple reason that he was comfortably dozing.

the sub looked at the clock in the bulkhead. it was a quarter-past eight. although it was day, no natural light penetrated the interior of the hull. the submarine was running on the surface. the pulsation of the internal combustion engines proved that.

a man clad in blue cloth trousers, sweater and sea-boots entered the compartment and began to remove the empty plates.

"had a good tuck in, chum?" he inquired. "all right—best turn in for a spell. there's your bunks, blankets and all. captain won't want to see you afore three bells in the second dog."

"thank you," replied broadmayne. he, too, was feeling drowsy. perhaps it was the heat of the confined space. he touched vyse on the shoulder.

"turn in, old man!" he exclaimed.

"what for?" demanded his chum rebelliously; then his desire to sleep dominated all other inclinations. merely kicking off his rubber-boots, vyse turned in all standing. the sub followed his example, and a couple of minutes later both men were lost in heavy, dreamless slumber.

meanwhile captain cain, whose almost unbounded energy could keep him going at high pressure for thirty-six hours without any desire for sleep, was standing on the bridge of the alerte as she stood southward at eight knots.

he was at the wheel. with the exception of one mechanic standing by the diesel motors, all hands were enjoying a few hours' well-earned rest. shortly after the crew of the ibex had been taken on board, a wireless message had been picked up that gave captain cain an inspiration upon which he determined to act.

the wireless message was from the norddeutscher-lloyd intermediate boat cap hoorn, to the ushant signalling-station, reporting that she was ninety miles w. by s. of ushant, homeward bound from bremen.

already the pirate captain had "looked her up" in the shipping register. he found that the cap hoorn was a vessel of 8500 tons, with a speed of fifteen knots. coming from buenos ayres and rio, she would be certain to have a valuable cargo. it was a risky business to hold her up, but captain cain, having weighed the pros and cons, decided to intercept her.

at noon the alerte's crew were roused. preparations were immediately started to disguise the ship. the funnel was given a different coloured coat of paint; the masts, previously light brown with black above the hounds, were painted a uniform shade of dark grey. the bridge and funnel were bodily shifted twenty feet aft, and the position of the ventilating cowls altered. finally, on both bows and astern the name alerte was covered by strips of painted cloth bearing the name cimeterre, and the french tricolour hoisted aft.

"i'm going to put the breeze up a hun, my lads," he announced. "she's now on her way up-channel. she's a lump of a boat, but we'll get her. remember that for this occasion you're frenchmen. when we board her, keep your mouths shut and let mr. pengelly grease his jaw-tackle. he can speak french like a native and german quite enough to make himself understood. i'm not going to hurt fritz more than i can help. it depends upon himself. if she heaves to, as i expect she'll do, mr. pengelly will take half a dozen hands, all armed, and see what's of use to us——"

"sail on the starboard beam, sir!" shouted the look-out man. "black hull, white top-hamper, two funnels all yellow."

"that's our pigeon," declared pengelly; then noticing his partner glare, he hastened to add the previously omitted "sir."

"very good, mr. pengelly," sang out the captain. "tell off your boat's crew in readiness. fall in, q. f. numbers; signalman, stand by and hoist the i. d."

the alerte and the cap hoorn were approaching almost at right angles to each other's course. as the positions of the ships went, the alerte would bring the german's port side on her starboard bow, in which case, under the "rules and regulations for preventing collisions at sea," the former had to give way.

nearer and nearer came the huge norddeutscher-lloyd vessel, showing the "bone in her jaw" as she flung out a tremendous bow-wave. unswervingly, both vessels held on. the cap hoorn blew a warning blast on her syren.

"hard-a-starboard!" ordered captain cain, at the same time motioning the alert signalman. round swept the alerte, until she was on a parallel course to that of her victim. the screens concealing the quick-firer were lowered and the muzzle of the weapon swung round. simultaneously the signal i. d. (heave-to, or i will fire into you) was hoisted; followed, without waiting for the cap hoorn's reply, by lda—zmx (disconnect your wireless apparatus).

the two vessels were now roughly four hundred yards apart. through his binoculars, captain cain observed with considerable satisfaction that the german officers and men were in a state of panic, while the passengers, guessing that something was amiss but ignorant of the true state of affairs, crowded to the side.

the pirate captain rang for full speed ahead. almost immediately, the pulsations of the motors increased, and the alerte quickly attained her maximum speed, equal to that of the cap hoorn.

still the latter showed no sign of stopping her engines. from her bridge a three flag hoist went up.

"wcx, sir!" reported the alerte's signalman, as he rapidly turned over the pages of the code book, adding as he discovered the message, "signals not understood, though flags are distinguished."

"more bluff!" ejaculated captain cain. "i'll send 'em a message that won't bear misunderstanding. captain of the gun!" he continued, raising his voice. "give her one above the waterline. knock her rudder-head to smithereens."

the quick-firer spat viciously. considering the gun-layer had had no previous experience with that particular type of weapon, the result was highly creditable to his professional skill.

the projectile struck the cap hoorn about ten feet for'ard of the rudder and about four feet above the waterline. it made a clean hole where it entered, but of the devastating effect of the explosive shell there was little doubt. splinters and slivers of metal flew high in the air. flames and smoke poured from a jagged hole in the poop. the red, white and black ensign, its staff shattered by the explosion, was whisked fifty yards astern.

twenty seconds later the cap hoorn's propellers were going astern; but owing to the rudder-head being pulverised, the massive rudder swung hard over to starboard. slowly her head began to pay off towards her antagonist. men armed with fire extinguishers and hoses were seen running aft. with indecorous haste another german mercantile ensign was hoisted and as promptly lowered in token of surrender.

"look alive, mr. pengelly!" exclaimed the pirate captain. "you know your orders?"

"ay, ay, sir," was the reply.

a boat was lowered. into it went pengelly and half a dozen men, all armed with automatic pistols. by this time captain cain had got way off his ship, the two vessels being now about a cable's length apart.

the boat's crew gave way with a will, their comrades, with the exception of the men at the quick-firer, crowding to the side to watch their progress.

"mr. barnard!" shouted captain cain.

the bo's'un doubled aft and saluted.

"what's that man doing on deck?" inquired the skipper angrily, pointing to gerald broadmayne, who, unobserved by the hands on deck, had come up from below and was watching the unusual sight.

"dunno, sir," replied mr. barnard helplessly. "both of 'em were sound asleep when last i looked in."

as a matter of fact, the bo'sun, in the excitement of the one-sided enjoyment, had completely forgotten about the presence of the two strangers on board. he had omitted to lock the door between the men's quarters and the vestibule immediately underneath the base of the conning-tower.

"all right, let him alone," decided captain cain, as he reflected grimly that now the cat was out of the bag, his involuntary guests would have to remain on board at all costs, until the termination of the cruise, wherever and whenever it might be.

"so that's the game, is it?" thought the sub. his searching eyes quickly took in the evidence of the incriminating surroundings—the quick-firer trained abeam, with a still smoking shell-case lying close to the mounting; the french ensign floating over a vessel whose crew were british and, for the most part, west-country folk; the men all armed with automatic pistols; least and not last a boarding party on their way to the disabled german liner. "piracy—out and out piracy."

like those of the alerte's crew who remained on board, broadmayne found his interest centre on the boat containing pengelly and his armed companions.

before the boat had ranged up alongside the cap hoorn, the german crew had lowered the accommodation-ladder.

headed by pengelly, the boarders ran up the ladder. at the gangway they were met by the captain and several of the officers of the captured vessel; while gathered at a respectful distance were about thirty of the crew and those of the passengers whose curiosity had overcome their timidity.

there was no sign of resistance. pengelly, escorted by the german captain, disappeared from view, three of his men following him. the others, with the exception of the boat-keeper, drove the passengers and crew for'ard like a flock of sheep.

"no guts!" soliloquised broadmayne scornfully. "can you imagine a british ship with that sized crew chucking up the sponge? they'd rush the blighters even if they only had broomsticks."

presently one of the alerte's boarders at the head of the accommodation-ladder held up a small white flag. it was a pre-arranged signal. as long as it remained held aloft, it indicated that the looters were having things all their own way. should the germans turn upon their captors, the white flag would be dropped. then, and only then, would the alerte's quick-firer pump shell after shell into the huge target presented by the motionless cap hoorn.

twice there came the dull report of an explosion. the crew of the quick-firer tautened, the captain of the gun looking inquiringly at the imperturbable figure on the alerte's bridge. but captain cain gave no sign. the white hand-flag was still conspicuously displayed at the gangway of the prize. occasionally he swept the horizon with his binoculars, ready at the first sign of an approaching craft to recall his merry men and seek safety in flight.

an hour and ten minutes after the boat had pushed off from the alerte, pengelly descended the cap hoorn's accommodation-ladder. the boat, heavily laden, headed back to her degenerate parent and was hoisted up in davits.

"well?" inquired captain cain laconically.

"skinned 'em, sir," replied pengelly, with a broad grin.