Who is the alleged Chinese drug kingpin suspected to be the ‘critical link’ of Mexico’s drug trade? At the height of the fentanyl crisis in the US, Zhang Zhidong, also known as ‘Brother Wang’, is alleged to have facilitated the production and movement of the drug across borders. His ability to embed himself into different cultures is claimed to have made him a key part of the drug supply chain between China, Mexico and the US. Tap the link in BBCNews’s bio for more on this story. #BBCGlobalEye #BBCNews