Dirt

'Have you ever thought about what it would be like to dig upwards George?'

'What?' replied George snappily struggling as he was with the breaking of a peculiarly stubborn rock, 'What in earth are you going on about?', and he crashed the pickaxe down, finally splitting the stone into three more manageable pieces; it was clear that he didn't appreciate the interruption.

'Up there?' Milly replied, pointing up at the vast expanse of brown mud and grit above her head that had been their sky for as long as she could ever remember, 'Have you ever thought about, you know, just digging upwards, up to the sky?'

'Of course I haven't Milly, why would I? And more to the point why would you? It's not worth even thinking about, you know that'.

'Oh I don't know', she said as she moved slowly down to pick up the iron rake used to clear away smaller rocks, 'don't you ever just get bored? With all this digging I mean. Have you never thought about what it's like up there?'