Chronicles of Narnia:
The Voyage of the Dawn Treader
By C.S. Lewis
"'Oh Aslan,' said Lucy. 'Will you tell us how to get into your country from our world?'
'I shall be telling you all the time,' said Aslan. 'But I will not tell you how long or short the way will be; only that it lies across a river. But do not fear that, for I am the great Bridge Builder.'
[Aslan tells Lucy and Edmund they have to go back to our world and will never come back to Narnia again...]
'It isn't Narnia, you know,' sobbed Lucy. 'It's you. We shan't meet you there. And how can we live, never meeting you?'
'But you shall meet me, dear one,' said Aslan.
'Are--are you there too, Sir?' said Edmund.
'I am,' said Aslan. 'But there I have another name. You must learn to know me by that name. This was the very reason why you were brought to Narnia, that by knowing me here for a little, you may know me better there.'"