He got on his knees and one hand, holding the torch with the other, and crept after her.
The hole twisted about, in some parts so low that he could hardly get through, in others so high that he could not see the roof, but everywhere it was narrow--far too narrow for a goblin to get through, and so I presume they never thought that Curdie might.

He was beginning to feel very uncomfortable lest something should have befallen the princess, when he heard her voice almost close to his ear, whispering: 'Aren't you coming, Curdie ?' And when he turned the next corner there she stood waiting for him.
'I knew you couldn't go wrong in that narrow hole, but now you must keep by me, for here is a great wide place,' she said.
'I can't understand it,' said Curdie, half to himself, half to Irene.
'Never mind,' she returned.

'Wait till we get out.' Curdie, utterly astonished that she had already got so far, and by a path he had known nothing of, thought it better to let her do as she pleased.

'At all events,' he said again to himself, 'I know nothing about the way, miner as I am; and she seems to think she does know something about it, though how she should passes my comprehension.

So she's just as likely to find her way as I am, and as she insists on taking the lead, I must follow.