Nitazenes are a new form of illicit drug entering the UK. Made in Chinese laboratories, the synthetic opioids have been linked to a growing number of deaths. This programme investigates how the highly potent drugs are being smuggled into the country from China. Is it possible to track down the dealers behind the trade, and just how are they advertising their business? We hear from the families and friends who have lost loved ones to nitazenes, a drug type termed 'Frankenstein opioids' because of the catastrophic effects. Is enough being done to prevent this supply and potential future deaths?