Do you see a slab laid up against the wall ?' Irene looked, and felt about with her hands, and soon perceived the outlines of the slab.
'Yes,' she answered, 'I do.' 'Then, I think,' rejoined Curdie, 'when you have cleared the slab about half-way down, or a bit more, I shall be able to push it over.' 'I must follow my thread,' returned Irene, 'whatever I do.' 'What do you mean ?' exclaimed Curdie.

'You will see when you get out,' answered the princess, and went on harder than ever.
But she was soon satisfied that what Curdie wanted done and what the thread wanted done were one and the same thing.

For she not only saw that by following the turns of the thread she had been clearing the face of the slab, but that, a little more than half-way down, the thread went through the chink between the slab and the wall into the place where Curdie was confined, so that she could not follow it any farther until the slab was out of her way.

As soon as she found this, she said in a right joyous whisper: 'Now, Curdie, I think if you were to give a great push, the slab would tumble over.' 'Stand quite clear of it, then,' said Curdie, 'and let me know when you are ready.' Irene got off the heap, and stood on one side of it.

'Now, Curdie!' she cried.
Curdie gave a great rush with his shoulder against it.