'Eddies,' said Ford, 'in the space-time continuum.'
'Ah,' nodded Arthur, 'is he? Is he?' He pushed his hands into the 
pocket of his dressing gown and looked knowledgeably into the 
distance.
'What?" said Ford.
'Er', who,' said Arthur, 'is Eddy, then, exactly, then?'
Ford looked angrily at him.
'Will you listen?' he snapped.
'I have been listening,' said Arthur, 'but I'm not sure it's helped.'
Ford grasped him by the lapels of his dressing gown and spoke
to him as slowly and distinctly and patiently as if he were somebody
from a telephone company accounts department.
'There seem...' he said, ' to be some pools...' he said, 'of 
instability...' he said, 'in the fabric...' he said...
Arthur looked foolishly at the cloth of his dressing gown where
Ford was holding it. Ford swept on before Arthur could turn the
foolish look into a foolish remark.
'...in the fabric of space-time', he said.
'Ah, that,' said Arthur.
'Yes, that', confirmed Ford.
They stood there alone on a hill on prehistoric Earth and stared 
each other resolutely in the face.
'And it's done what?', said Arthur.
'It,' said Ford, 'has developed pools of instability.'
'Has it?' said Arthur, his eyes not wavering for a moment.
'It has,' said Ford with a similar degree of occular immobility.
'Good,' said Arthur.
'See?' said Ford.
'No,' said Arthur.
There was a quiet pause.
'The difficulty with this conversation,' said Arthur after a sort
of pondering look had crawled slowly across his face like a 
mountaineer negotiating a tricky outcrop, 'is that it's very different from
most of the ones I've had of late. Which, as I explained, have
mostly been with trees. They weren't like this. Except perhaps some
of the ones I've had with elms which sometimes get a bit bogged
down.'
'Arthur,' said Ford.
'Hello? Yes?' said Arthur.
'Just believe everything I tell you, and it will all be very, very simple.'
'Ah, well I'm not sure I believe that.'