And far away in the distance, from the heart of the great factory, came a muffled roar of energy as though some monstrous gigantic machine were spinning its wheels at breakneck speed.

'Now this, my dear children,' said Mr Wonka, raising his voice above the noise, 'this is the main corridor. Will you please hang your coats and hats on those pegs over there, and then follow me. That's the way! Good! Everyone ready? Come on, then! Here we go!' He trotted off rapidly down the corridor with the tails of his plum-coloured velvet coat flapping behind him, and the visitors all hurried after him.

It was quite a large party of people, when you came to think of it. There were nine grown-ups and five children, fourteen in all. So you can imagine that there was a good deal of pushing and shoving as they hustled and bustled down the passage, trying to keep up with the swift little figure in front of them. 'Come on!' cried Mr Wonka. 'Get a move on, please! We'll never get round today if you dawdle like this!'

Soon, he turned right off the main corridor into another slightly narrower passage.

Then he turned left.

Then left again.

Then right.

Then left.

Then right.

Then right.

Then left.

The place was like a gigantic rabbit warren, with passages leading this way and that in every direction.

'Don't you let go my hand, Charlie,' whispered Grandpa Joe.

'Notice how all these passages are sloping downwards!' called out Mr Wonka. 'We are now going underground! All the most important rooms in my factory are deep down below the surface!'

'Why is that?' somebody asked.