Who was that unseen man? Whoever he was he held old Benjamin Keppel in his power, and to his diabolical plot would be due the destruction of the Vispera and perhaps the loss of every soul on board. He had suggested an explosion. He no doubt intended to place on board some infernal contrivance which, after the lapse of a certain number of hours, would explode and blow the bottom out of the yacht. Whoever that man was he was a crafty villain. Providentially, however, I had been led to the discovery of the scheme, and I did not mean that the lives of my fellow-guests or of the crew should be sacrificed in order to conceal a crime. A vision of that white, dead face recurred to me. It was the face of a woman who had once been very handsome, but to my remembrance I had never seen it before. The mystery of the woman’s concealment there was altogether extraordinary. Yet it scarcely seemed possible that she should have remained in hiding so long without a soul on board save Keppel being aware of her presence. She had been fed, of course, and most probably the steward knew of her presence in that gilded deck-house. But she was dead--murdered by the inoffensive old gentleman who was the very last person in the world I should have suspected of having taken human life. And why had he stroked her dead face so caressingly? Who, indeed, was she? My wet clothes clung to me cold and clammily, therefore I exchanged them for a warm wrap, and entering my berth tried to rest. Sleep was, however, impossible in that doomed ship amid the wild roaring of the tempest and the thunder of the waves breaking over the deck above. Once it occurred to me to go straight to Ulrica and tell her all I had seen and heard, but on reflection I resolved to keep my own counsel and narrowly watch the course of events. The mystery of the hidden man’s identity grew upon me, until I suddenly resolved to make a further endeavor to discover him. The voice was deep and low, but the roaring of the wind and hissing of escaping steam had prevented me hearing it sufficiently clearly to recognize whether it was that of one of our fellow-guests. I slipped on a mackintosh, and returning to the deck crept towards the cabin wherein reposed the remains of the mysterious woman in white serge. But soon I saw that the light had been switched off. All was in darkness. The guilty pair had gone below to their own berths. Through the whole night the storm continued, but the morning broke brightly and the tempest, as is so frequent in the Mediterranean, was succeeded by a dead calm, so that when we sat down to breakfast we were steaming in comparatively smooth water. “Have you heard?” said Ulrica across to me after we had been exchanging our sleepless experiences. “Mr. Keppel has altered our course. He has some pressing business to attend to, so we are going into Leghorn.”