others were Dutch. Pity that Dekker has never ventured beyond the frontiers of his own homeland. He might - I say just might - have been able to identify the country of origin of the owner of that voice. I speak two or three languages, Peter, you even more. Do you think, if we'd heard this person speaking, we'd have been able to tell his country?' 'There's a chance. I wouldn't put it higher than that. I know what you're thinking, sir. The tape-recording that this newspaper sub-editor made of the phone call they received. Chances there would be much poorer - you know how a phone call can distort a voice. And they don't strike me as people who would make such a fairly obvious mistake. Besides, even if we did succeed in guessing at the country of origin, how the hell would that help us in tracking them down?'
De Graaf lit up a very black cheroot. Van Effen wound down his window. De Graaf paid no attention. He said: 'You're a great comforter. Give us a few more facts - or let's dig up a few more - and it might be of great help to us. Apart from the fact, not yet established, that he may be a foreigner, all we know about this lad is that he's very tall, built along the lines of an emaciated garden rake and has something wrong with his eyes.' 'Wrong? The eyes, I mean, sir? All we know for certain is that he wears sun-glasses at. night-time. Could mean anything or nothing. Could be a fad. Maybe he fancies himself in them. Maybe, as Dekker suggested, he thinks sun-glasses are de rigueur for the better class villain. Maybe, like the American President's Secret Service body-guards, he wears them because any potential malefactor in a crowd can never know whether the agent's eyes are fixed on him or not, thereby inhibiting him from action. Or he might be just suffering from nyctalopia.'
'I see. Nyctalopia. Every schoolboy knows, of course. I am sure, Peter, that you will enlighten me at your leisure.'
'Funny old word to describe a funny old condition. I am told it's the only English language word with two precisely opposite meanings. On the one hand, it means night-blindness, the recurrent loss of vision after sunset, the causes of which are only vaguely understood. On the other hand, it can be taken to
day-blindness, the inability to see clearly except by night, and here the causes are equally obscure. A rare disease, whatever meaning you take, but its existence has been well attested to.
The sun-glasses, as we think of them, may well be fitted with special correctional lenses.'
'It would appear to me that a criminal suffering from either manifestation of this disease would be labouring under a severe occupational handicap. Both a house-breaker, who operates by daylight, and a burglar, who operates by night, would be a bit restricted in their movements if they were afflicted, respectively, by day or night blindness. just a little bit too far-fetched for me, Peter. I prefer the old-fashioned reasons. Badly scarred about the eyes. Cross-eyed. Maybe he's got a squint. Maybe an eye whose iris is streaked or parti-coloured. Maybe wall-eyed, where the iris is so light that you can hardly distinguish it from the white or where the pupils are of two different colours. Maybe a sufferer from exophthalmic goitrc, which results in very protuberant eyes. Maybe he's only got one eye. In any event, I'd guess he's suffering from some physical abnormality by which he would be immediately identifiable without the help of those dark glasses.'
'So now all we've got to do is to ask Interpol for a list, world-wide, of all known criminals with eye defects. There must be tens of thousands of them. Even if there were only ten on the list, it still wouldn't help us worth a damn. Chances are good, of course, that he hasn't even got a criminal record.' Van Effen pondered briefly. 'Or maybe they could give us a list of all albino criminals on their books. They need glasses to hide their eyes.
'The Lieutenant is pleased to be facetious,' de Graaf said