Francis Saxover, a Cambridge scientist, hits on a discovery which as he modestly remarks, is ‘in the megaton range’ it is that SF favourite, an antidote to old age, of ‘Antigerone’, as its discoverer calls it, and it raises the expectation of life to between 200 and 300 years.

But the lichen from where it is derived is scarce, only enough to preserve a few thousand people. Any announcement of the discovery would start a stampede like a gold rush. So Saxover, in the agonies of indecision, keeps his secret. But it is not his only. A former colleague has also discovered Antigerone…