Dr Benson opened and closed his desk drawer again. ‘The blight is appearing on all kinds of crops in all kinds of regions. Not just on wheat in the plains states. But on apples and pears and broccoli and peas and tomatoes and you name it. Every region is concerned about it, but so far it doesn’t appear to have spread widely enough for anyone in the Federal Department of Agriculture to have twigged on to what’s happening. So the grape growers lose a few table grapes. So the tomato growers lose a few bushels of tomatoes. Every farmer has his problems, and farming’s an industry with plenty of natural wastage.

‘But,’ said Dr Benson, walking across to the window and staring out at the shadowed courtyard below him, ‘all my conversations yesterday afternoon and early this morning with research staff in six states – just to ask for ideas to begin with, just to seek opinions – all my conversations seem to have led me to one very uncomfortable conclusion. Which is why I started wondering about a Soviet conspiracy. The one very uncomfortable conclusion is that all these crop disorders are caused by manifestations of the same basic virus. Maybe a slightly different version for celery. Maybe a specially high-powered one for potatoes. But all the same fundamental malignancy – all causing the same kind of effect. Blackness and decay and a rot that spreads like a forest fire.’

Ed could hardly believe what he was hearing. ‘You mean, all of these states are suffering the same sort of problem – and nobody’s taken an overview? Nobody’s realised that it’s the same thing?’

‘Why should they? It’s all happened in the space of a few days. Maybe a week or two at the most. And you have to remember that most state agricultural departments work in a very bureaucratic way. They have no reason to operate otherwise. It takes a long dime for one farmer’s complaint about a few blighted nectarines to filter its way through the office structure and then the research structure and finally arrive on some responsible officer’s desk, so that he can connect it with another farmer’s complaint about blighted celery. That’s if he ever connects it at all.’

Dr Benson turned around, and the light from the window made a crescent of reflected whiteness in his glasses. ‘You also have to remember that many of our agricultural research people aren’t exactly – well, to put it quite charitably – they aren’t exactly hotshots. The fellow I talked to in Modesto had examined twenty-eight samples of blighted fruit and vegetables, and he wasn’t even considering the possibility of a virus.’