Two propositions lie at the centre of this book. First, we should all give up medical screenings and get on with a jolly life, embracing the inevitability of death. Second, our immune systems abet the growth and spread of tumours. The beastly cells that do this are called macrophages. What can we learn about our bodies’ ability to destroy themselves?

Barbara Ehrenreich is a prolific American author whose books include Nickel and Dimed, about the low-wage economy, and Smile or Die: How Positive Thinking Fooled America and the World. A cellular immunologist, in the 1960s she did graduate research on macrophages, but at that time their nefarious role was not known. Scientists have only recently discovered how macrophages and tumour cells can pool their resources and overwhelm the human organism (macrophages can account for up to 50 per cent of a tumour’s mass). Ehrenreich was shocked when the news came out in the medical literature and seems to think that the cells betrayed her: ‘I thought they were my friends.’ She returns to this theme often.

The narrative poses the question, ‘How far can we control our health?’ Over the course of her mostly pleasantly meandering book, Ehrenreich realises that this is part of a larger question about ‘whether the natural world is dead or in some sense alive’. She is an accomplished writer