The glare of the red light behind waxed fiercer still, and a low rumbling as of distant thunder began to mutter round us. The air became difficult to breathe. It was no longer air, but a mephitic stench that choked us with disgusting fumes. Then a great shock shook the land, and right in front of us a seam opened that must have been fully fifteen feet in width. Natalie was the first to see it. She observed it too late to stop. In the same mechanical way as she had acted before, she settled herself in the saddle, struck the pony with her hand, and raced him at the chasm. He cleared it with little to spare. Edith's took it next with less. Then my turn came. Before I could shake up my tired horse, Mademoiselle Véret said quickly: "Monsieur has done enough. He will now permit me to alight. This time the horse cannot jump over with both." "He shall jump over with both, Mademoiselle, or he shall jump in," I answered. "Don't look down when we are crossing." The horse just got over, but he came to his knees, and we fell forward over his shoulder. The girl's head struck full on a slab of rock, and a faint moan was all that told me she was alive as I arose half stunned to my feet. My first thought was for the horse, for on him all depended. He was uninjured, apparently, but hardly able to stand from the shock and the stress of fatigue. Edith Metford had dismounted and caught him; she was holding the bridle in her left hand, and winced as if in pain when I accidentally brushed against her right shoulder. I tied the horse to a young palm, and begged the girl to ride on. She obeyed me reluctantly. Natalie had to assist her to remount, so she must have been injured. When I saw her safely in her saddle, I ran back to Mademoiselle Véret. The chasm was fast widening. From either side great fragments were breaking off and falling in with a roar of loose rocks crashing together, till far down the sound was dulled into a hollow boom. This ended in low guttural, which growled up from an abysmal depth. Mademoiselle Véret, or her dead body, lay now on the very edge of the seam, and I had to harden my heart before I could bring myself to venture close to it. But I had given my word, and there were no conditions in the promise when I made it. I was spared the ordeal. Just as I stepped forward, the slab of rock on which the girl lay broke off in front of me, and, tipping up, overturned itself into the chasm. Far below I could see the shimmer of the girl's dress as her body went plunging down into that awful pit. And remembering her generous courage and offer of self-sacrifice, I felt tears rise in my eyes. But there was no time for tears. I leaped on the bay, and got him into something approaching a gallop, shouting at the others to keep on, for they were now returning. When I came up with them, Edith Metford said with a shiver: "The girl?" "Is at the bottom of the pit. Ride on."