The swiftest of them, the Tonnant, a French cruiser, forged ahead while the others forced their draught in an effort to catch up with her.
The Tonnant, at the risk of being blown to pieces in turn, penetrated the danger zone half a mile, and then ran up her flag while manoeuvring to bring her heavy guns into action.
From the bridge the officers could see Ker Karraje’s band scattered on the rocks of the island.
The occasion was an excellent one for getting a shot at them before the bombardment of their retreat was begun, and fire was opened with the result that the pirates made a rush to get into the cavern.
A few minutes later there was a shock terrific enough to shake the sky down.
Where the mountain had been, naught but a heap of smoking, crumbling rocks was to be seen. Back Cup had become a group of jagged reefs against which the sea, that had been thrown back like a gigantic tidal wave, was beating and frothing.
What was the cause of the explosion?
Had it been voluntarily caused by the pirates when they realized that escape was impossible?
The Tonnant had not been seriously damaged by the flying rocks. Her boats were lowered and made towards all that was left of Back Cup.
The landing parties explored the ruins, and found a few horribly mangled corpses. Not a vestige of the cavern was to be seen.