A livid flash leapt from under the Surcouf's bridge, followed almost immediately by a sharp report. Before any one on board the Alerte realised what had happened a seven-pounder shell burst against the dummy superstructure amidships, ripped a jagged hole in the funnel and cut away the mainstay, with the result that the mainmast, wrenching away the steel tabernacle, crashed heavily upon the poop.
Captain Cain was one of the first to grasp the situation. With all his faults, he was not lacking in courage when under fire. A sliver of metal had grazed his forehead, laying open the frontal bone; but in the excitement he did not heed the burning pain.
"Let 'em have it on the waterline, Gunner's mate," he shouted, countermanding his previous order to destroy the Frenchman's wireless gear.
Since he could not effect the capture of the Surcouf without resistance, he determined to sink her. It meant the loss of the expected booty, but the Alerte could not run the risk of a prolonged action. There was little danger of the hull of the submarine being perforated by the Frenchman's light quick-firer. Even if the outer skin were holed the inner plating would successfully impede the progress of the projectile. The dominating factor was the absence of any repairing base to which the Alerte could retire to heal her wounds. Whatever damage was received had to be made good on the high seas, and a badly battered craft would naturally be the object of interest if not of suspicion.
The gun's crew of the Alerte's quick-firer rose to the occasion. As fast as the breech-block could be open and snapped to, the powerful weapon spoke. Empty cartridge-shells clattering on the steel deck punctuated the sharp bark of the weapon, while shell after shell at point-blank range crashed into the Surcouf's hull.
But the Frenchman, in spite of the disproportionate odds in the matter of ordnance, maintained a steady fire, not only from the gun under the bridge, but from a similar weapon mounted aft. She then began to go astern, until the Alerte's quick-firer was masked by the stanchions of her bridge.
By this time the Surcouf's hull was holed in twenty places. A fire had broken out amidships, smoke was pouring in volumes from a dozen jagged apertures; yet not a single shell had hit her 'twixt wind and water.
For nearly a minute the Alerte was raked aft without being able to reply. Two of the hands rushed towards the poop with the machine-gun. Before they reached their goal both were struck down by splinters of shell from a missile that had exploded against one of the cowls.
"Port eight, Quartermaster!" shouted Captain Cain. "Now, lads, let her have it!"
But even as the Alerte swung to starboard the Surcouf put her helm hard over. She was not "out" to sink a pirate, or be sunk herself. Her duty lay in saving her precious cargo.