The Covid-19 pandemic has been one of the weirdest things any of us has lived through. But there was another sickness that once stalked the nation and turned things very strange for a while.

In the 1990s Britain was hit by an epidemic of a fatal neurological disease in cows that also killed 178 humans. Science was split between government assurances of safety and dissidents warning of disaster. Trust in officials took a battering. Facts became blurred. And the grisly truth about our global industrialised meat industry was revealed.

30 years on, scientists and activists are still searching for answers to two big questions - where did mad cow disease originally come from and how did humans get infected? This crazy tale of cannibal cows, competing origin theories, and scientific dead ends lives on as the madness continues to spread.