BTB can be harmful to humans and is fatal for cattle. Managing a breakdown can be economically disastrous and extremely stressful for farmers. The campaign to eradicate bTB combines challenging diagnostic science, field-by-field biosecurity, veterinary monitoring and political will. Glossop is Chief Veterinary Officer for Wales, and has made the implementation of a comprehensive TB eradication programme her highest priority. Hewinson is a globally respected scientist in the field of TB immunology and diagnostics, who worked on the collaborative project that led to the sequencing of the M Bovis genome. They talk to Peter Florence.