On 13 February 2017, the North Korean dictator's half-brother Kim Jong-nam walked into Kuala Lumpur airport to catch a flight to Macau. Two hours later he was dead. He had been assassinated using one of the most deadly chemical weapons on earth - VX. Within days, two women from Vietnam and Indonesia were arrested for his murder, but the CCTV appeared to show several North Korean secret agents orchestrating the events in the airport that day. With brand new accounts from those close to Kim Jong-nam, the award-winning This World strand examines in greater detail the astonishing story of a bitter family feud, secret agents and international arms dealing, lifting the lid on why he was assassinated and how North Korea's powerful international business network has allowed the brutal Kim family dictatorship to remain in power in North Korea for nearly 70 years.