S1, E1: Fifteen years prior to Line Of Duty hitting our screens, a little-known unit of the Metropolitan Police was being secretly set up to crack the cycle of corruption that infiltrated the country’s biggest police force. The unit was CIB3 and its purpose? To expose corrupt police officers and bring them to justice. One of the first targets was former Met Detective Duncan Hanrahan, and with the newly formed CIB3 ready to go, Operation Eden was put into motion.