Kate Grenville had always associated perfume with elegance and beauty. Then the headaches starred. On a book tour, dogged by ill health, she started wondering: what's in fragrance? What does it do to people? The more Grenville investigated, the more she felt this was a story that should be told. Fragrance isn't made of flowers now, but synthetic chemicals. Some of them can be linked not just to headaches, but to asthma and allergies, hormone disruption...