As the families of those on board flight Pan Am 103 learn that the passenger plane has crashed over Lockerbie, a terrorism investigation tries to find out what happened.

While forensic evidence suggests the prime suspects for the bombing of Pan Am 103 are a Palestinian terror group funded by Iran, Scottish and FBI investigators are eventually led elsewhere.

The CIA hands over a Libyan double agent who provides crucial evidence needed to bring the two bombing suspects to court, but the key witness changes his story as the trial gets underway.

The court makes a shock verdict that leaves the victims' families unsatisfied and casts doubt on the decision.