On 21 December 1988, a bomb detonates on board Pan Am flight 103 above Lockerbie, Scotland. The attack kills 270 people and shocks the world. The Scottish police and FBI must join forces to find the perpetrators. The Bombing of Pan Am 103 is a six-part factual drama based on the real events surrounding the Lockerbie disaster and the international investigation to find those responsible for the attack and bring them to justice.

Evidence is discovered amid the wreckage that could represent a potential breakthrough. It suggests that the Lockerbie bomb bears the accidental signature of a known terrorist organisation. This could change the course of the entire investigation. Representatives of the Scottish police head to Washington to collaborate with their FBI colleagues and share vital new evidence. Progress looks promising, but the CIA appears to be withholding crucial intelligence on a possible bombmaker.