We certainly were. The _Lightning Loose_ was going faster and faster along that subterranean channel, and every now and then gave a lurch and a shiver. 'Oh!' whined Brenda; 'this is a dreadful place for dear little dogs!' 'Philip!' said Lucy in a low voice, 'I know something is going to happen. Something dreadful. We _are_ friends, aren't we?' 'Yes,' said Philip firmly. 'Then I wish you'd kiss me.' 'I can like you just as much without that,' said Philip uneasily. 'Kissing people--it's silly, don't you think?' 'Nobody's kissed me since daddy went away,' she said, 'except Helen. And you don't mind kissing Helen. She _said_ you were going to adopt me for your sister.' 'Oh! all right,' said Philip, and put his arm round her and kissed her. She felt so little and helpless and bony in his arm that he suddenly felt sorry for her, kissed her again more kindly and then, withdrawing his arm, thumped her hearteningly on the back. 'Be a man,' he said in tones of comradeship and encouragement. 'I'm perfectly certain nothing's going to happen. We're just going through a tunnel, and presently we shall just come out into the open air again, with the sky and the stars going on as usual.' He spoke this standing on the prow beside Lucy, and as he spoke she clutched his arm. 'Oh, look,' she breathed, 'oh, listen!' He listened. And he heard a dull echoing roar that got louder and louder. And he looked. The light of the lamps shone ahead on the dark gleaming water, and then quite suddenly it did not shine on the water because there was no longer any water for it to shine on. Only great empty black darkness. A great hole, ahead, into which the stream poured itself. And now they were at the edge of the gulf. The _Lightning Loose_ gave a shudder and a bound and hung for what seemed a long moment on the edge of the precipice down which the underground river was pouring itself in a smooth sleek stream, rather like poured treacle, over what felt like the edge of everything solid. [Illustration: Plunged headlong over the edge.] The moment ended, and the little yacht, with Philip and Lucy and the parrot and the two dogs, plunged headlong over the edge into the dark unknown abyss below. 'It's all right, Lu,' said Philip in that moment. 'I'll take care of you.' And then there was silence in the cavern--only the rushing sound of the great waterfall echoed in the rocky arch. CHAPTER X THE GREAT SLOTH