Dee frowned. William was not all that old. But there was no need to correct Martin on that; the interesting thing was the salt issue. ‘He ate a lot of salt?’

‘I think so.’

‘Well, there you are,’ said Dee. ‘Sodium blockages. You know I’ll never forget when I went for iridology the first time and the iridologist looked into my eyes and said, “You eat a lot of salt.” And it was true. I really freaked out.’

Martin looked concerned. ‘How do they tell?’

‘Sodium rings in the eyes,’ said Dee. ‘It’s pretty obvious.’

Martin was silent. Then, after a few moments, ‘Could you tell? Yourself, I mean. Would you be able to tell if you looked into my eyes?’

Dee smiled. ‘Maybe. Do you want me to?’

It took Martin a minute or so to decide. Then he said, ‘Yes. It’s better to know, isn’t it?’

‘Of course you must know anyway,’ said Dee. ‘You must know whether you eat too much salt. Do you?’

Martin looked away. ‘Maybe sometimes.’

‘All right.’

There were no customers in the Vitamin and Supplement Agency at the time and Dee pointed to a chair in front of the counter. ‘Sit down, Martin. No, don’t close your eyes. I’m going to have to shine a light into them. Just relax.’

There was a small torch beside the cash register. They used it from time to time to look into the mouths of customers who wanted something for mouth ulcers or gingivitis. Dee reached for this torch and crouched in front of Martin. She rested a hand on his shoulder to steady herself. His shoulder felt bony; Martin did not eat enough, she thought, but that was something they could deal with later. For now it was sodium rings.

The torch threw a small circle of weak light onto his cheek. She moved it up closely until it was shining directly into his right eye.