"Three. One for you; another for Natalie; the third for myself. The rest must accept the fate they have selected." The girl shuddered as she said, "But your interference with the formula? You are sure it will destroy the effect?" "I am certain that the particular result on which Brande calculates will not take place. But short of that, he has still enough explosive matter stored to cause an earthquake. We are not safe within a radius of fifty miles. It will be a race against time." "Natalie will not come." "Not voluntarily. You must think of some plan. Your brain is quick. We have not a moment to lose. Ah, there she is! Speak to her." Natalie was crossing the open ground which led from the glen to Brande's laboratory. She did not observe us till Edith called to her. Then she approached hastily and embraced her friend with visible emotion. Even to me she offered her cheek without reserve. "Natalie," I said quickly, "there are three horses saddled and waiting in the palm grove. The _Esmeralda_ is still lying in the harbour where we landed. You will come with us. Indeed, you have no choice. You must come if I have to carry you to your horse and tie you to the saddle. You will not force me to put that indignity upon you. To the horses, then! Come!" For answer she called her brother loudly by his name. Brande immediately appeared at the door of his laboratory, and when he perceived from whom the call had come he joined us. "Herbert," said Natalie, "our friend is deserting us. He must still cling to the thought that your purpose may fail, and he expects to escape on horseback from the fate of the earth. Reason with him yet a little further." "There is no time to reason," I interrupted. "The horses are ready. This girl (pointing as I spoke to Edith Metford) takes one, I another, and you the third--whether your brother agrees or not." "Surely you have not lost your reason? Have you forgotten the drop of water in the English Channel?" Brande said quietly. "Brande," I answered, "the sooner you induce your sister to come with me the better; and the sooner you induce these maniac friends of yours to clear out the better, for your enterprise will fail." "It is as certain as the law of gravitation. With my own hand I mixed the ingredients according to the formula." "And," said I, "with my own hand I altered your formula." Had Brande's heart stopped beating, his face could not have become more distorted and livid. He moved close to me, and, glaring into my eyes, hissed out: "You altered my formula?" "I did," I answered recklessly. "I multiplied your figures by ten where they struck me as insufficient." "When?" I strode closer still to him and looked him straight in the eyes while I spoke.