Overdoses of the synthetic opioid fentanyl, which kills twice as many US citizens and 10 times as many Canadian people than firearms each year, are starting to increase in the UK and Europe; Vernon White, former Chief of Ottawa Police Service, and Joe Carlebach, former Hammersmith and Fulham councillor, explore the efforts being made to stem the supply of the precursor ingredients from China, and manufactured, street-grade fentanyl from Mexico and Canada.