Conspiracies have run wild about the origin of Coronavirus, but experts believe it is most likely that the virus originated from bats. SARS and Covid-19 are diseases that have crossed from other species into humans. This is not uncommon. However, with these particular diseases, the wet markets in China seem to have been the catalyst to this process. We decode how wet markets foster the conditions that promote the crossing of disease between species. Why has the Chinese government allowed these markets to flourish despite concerns about their safety? And how should the international community respond to this ongoing potential threat? With special thanks to: Prof David Heyman - London School of Hygiene and Tropical Medicine. Headed the global response to the SARS outbreak at the WHO. Katherine Mason - Medical Anthropologist at Brown University Prof Dirk Pfeiffer - Professor of Veterinary Epidemiology and Chair of One Health at City University of Hong Kong Dr Amesh Adalja - Senior Scholar at the Johns Hopkins University Centre for Health Security. Expert on emerging infectious disease, pandemic preparedness, and biosecurity. Sophia Yan - China correspondent, The Telegraph CREDITS Narrator Theodora Louloudis Archive Getty Director / Creative Lead Jeremy Holden Assistant Producer Elliott Daly Senior Producer Danielle Robinson Production Manager Carla de Nicola Research and Script Elliott Daly Jeremy Holden Film Editor Ed Gould Motion Designer Daniel Symons Music Audionetworks Executive Producer Andy Mackenzie Get the latest headlines: https://www.telegraph.co.uk/ Telegraph.co.uk and YouTube.com/TelegraphTV are websites of The Telegraph, the UK's best-selling quality daily newspaper providing news and analysis on UK and world events, business, sport, lifestyle and culture.