WARNING: Major spoilers for episode one ahead.

On December 21, 1988, the Swire family is abuzz with excitement as Flora Swire packs a suitcase for her first Christmas away from home with her boyfriend. Saying goodbye to her parents, Jane and Jim, and her brother William, she heads off in a car with sister Cathy to Heathrow Airport.

Boarding Pan-Am Flight 103 bound for New York, the flight is half-empty, but in good spirits. Flora and the other passengers start singing Christmas songs together as the flight takes off, but soon things go wrong, and a member of the cabin crew is thrown across the plane.

Meanwhile, in Lockerbie, Scotland, a young boy is taking his bike to get fixed, leaving his family at home watching TV. At Tundergarth Farm just outside the town, a farmer witnesses an explosion in the sky and soon, the entire town is engulfed in flames as debris and parts of the airplane start crashing to the ground, landing on homes, the streets, and people. A young boy, who left his family to get his bike fixed, returns to find his home no longer there.

News of the explosion quickly spreads around the UK, and a journalist heads to the scene, bearing witness to the chaos and devastation it's caused. In Berkshire, Jim returns home from his work as a GP ready for the festive season, when William sees the news bulletin. Soon, they’re panicking at the idea it was Flora’s flight.

In Lockerbie, police rally a search party in a bid to find survivors. A group head to Tundergarth Farm after receiving reports, and find a field littered with bodies. Among them, the farmer is seen cradling the body of a baby who was killed in the wreckage.

The others notice a group of men dressed in black, but the farmer notes they said they were crash investigators.

Jim frantically calls the Pan-Am help desk, but with hundreds of others across the world doing the same, he struggles to get through. When he does, it takes a while to get answers: but after several hours, he receives the news he was dreading – there are no survivors, and Flora was confirmed to be on the plane.

259 people were on board when the plane exploded.

In the days that follow, Pan-Am’s vice president states there was nothing to suggest there was something wrong with the airplane, and Margaret Thatcher gives her condolences to the lives lost.

On January 4th, 1989, a memorial service for the victims is held in Lockerbie. Among the attendees is Jim and Jane Swire, Prime Minister Thatcher, and transport secretary Paul Channon, whom Jim previously attended school with, albeit in different years. Jim grills Channon on whether the explosion was a revenge attack from Iran, and why he’s not been allowed to see Flora’s body yet, with all the victims being held at an ice rink nearby. Channon has no answers for him, but offers to help further down the line if he can.

Jim then meets Murray Guthrie, the reporter from the scene. Guthrie assures him he’s not there to intrude on his grief, but Jim jokingly replies that he doesn’t buy it. As the pair bond, Guthrie reveals an insider has told him the reason they’re not being allowed to see the bodies is because it would be deemed too traumatic for families – but suggests Jim use his position as a doctor to get into the ice rink.

While Jane begs him not to, Jim leaves the memorial and heads to the ice rink. When he arrives, he bears witness to rows of dead bodies covered in sheets. A doctor informs him he shouldn’t be there, but he begs to see his daughter. She obliges but says to be prepared. He hesitates but still does so, before breaking down, confirming Flora’s identity by a birthmark on her foot. In a moment of compassion, the doctor cuts off a lock of her hair for him to keep. He thanks her for her kindness, and leaves.

Guthrie visits the farmer to ask about the “crash investigators”. He says they were rooting through the belongings, and adds some people thought they saw FBI and CIA caps, but it was so chaotic it was hard to tell. But they were there before anyone else, and left early.

Guthrie later visits Jim at his GP office, and begins to feed him information from his research: including the fact there was a call from the US embassy in Helsinki on December 4 warning them of an impending attack, but it was dismissed as a hoax. A memo from the US embassy instructed workers not to fly on Pan Am before Christmas – but the public never got the memo. It’s rumoured that embassy staff had changed their flights after the memo - explaining the 165 empty seats on the plane despite being so close to Christmas.

He also flags Operation Autumn Leaves, where the police found bombs built into cassette players planned to be put on commercial flights. Similar to the damaged recording device found on Pan-Am Flight 103.

The information galvanises Jim into action, with him returning home and starting research of his own. Heading to the department of transport, Jim confronts Channon and shows him a restricted letter he’s been given, catching the minister off guard. Channon says it was a ‘general warning’ but they get them so often it was not taken seriously. When Jim demands answers, Channon promises to look into it, but is later revealed to have been fired from his position after being suspected of leaking privileged information to the press.

Jim and Jane start attending support group meetings for families and loved ones of those lost in the disaster. While the police have said there are now suspects, the group debate why those names haven’t been released. Jim reveals he’s reached out to the new transport secretary, Cecil Parkinson, requesting a meeting, but hasn’t had a response. He compares Lockerbie to another crash in Staines in 1972, which resulted in an independent inquiry, and proposes they fight for the same. The group names him their spokesperson.

Soon Jim is appearing on radio and TV to lobby for the inquiry into both the tragedy and the response of the government, but Parkinson continues to dodge him.

Jane discovers a letter to Flora from Cambridge University, accepting her onto a masters course to study medicine. Jane and Jim take a moment to commemorate her and the life she could have had if it wasn’t for the bombing.

Finally, Parkinson relents in September 1989, agreeing to meet with Jim, Jane and members of the support group. Before the meeting, Guthrie hands Jim his latest article, yet to be published, which confirms warnings from Frankfurt and a letter from the transport department ahead of the bombing to Heathrow Airport, instructing them to put suspicious looking items in the hold – which is where the Pan Am bomb was when it went off.

Parkinson argues the reason for this, rather than removing them from the flight completely, was to separate criminals from their “weapons” as most flight crimes are hijackings, but Jim says the letter proves there was a sufficient threat, made worse that the letter was sent late as they couldn’t get photocopies in time, therefore arriving after the bombings. He accuses the government of failure to alert airports to three legitimate threats, withholding information, and now denying their knowledge of what could happen.

Jim demands an inquiry, but Jane appears to move Parkinson most, admitting she had nightmares about Flora and whether she was conscious as she fell through the air to her death as research suggests she could have been awake for up to 15 seconds. Parkinson says he’ll make a request to the prime minister.

By November 1989, Thatcher denies an independent inquiry into the disaster, and Jim vows to never stop until they get answers for everything.

Moving forward to 2002, Jim is sitting in a prison, where a man is brought before him to sit down. Staring him in the face, he asks one simple question: “Did you kill my daughter?”

Henry Paul Guinness Channon was Conservative MP for Southend West from 1959 to 1997.

During his 38 years in office, Channon was appointed Transport Secretary in June 1987, and oversaw several major UK transport disasters – including the 1987 Kings Cross fire, the Clapham Junction rail crash of December 1988, and the Lockerbie disaster.

He was criticised by Labour’s John Prescott in the House Of Commons for taking a family holiday in Mustique in the Grenadines shortly after the disaster.

In January 1990, American journalist Jack Anderson reported that in March 1989, three months after the Lockerbie disaster, US President George Bush Sr had contacted Prime Minister Thatcher to request she back away from the investigation.

Around the same time, Channon had attended a luncheon at the Garrick Club alongside five political correspondents, and had declared the Dumfries and Galloway Police had concluded their investigation, found who was responsible, and an arrest was imminent. While the initial agreement of the event was to keep everything off-record, at least one journalist broke ranks and shared the news in the Daily Mirror. Channon denied being the source but neither sued nor complained. By July 1989, he was sacked from his position as Transport secretary.

At the support group, Jim compares the Lockerbie incident to the 1972 Staines disaster – although it should be noted that this was not a terrorist incident.

British Airways Flight 548 was flying from London Heathrow to Brussels on 18 June 1972 when it suffered a deep stall and crashed near Staines in Surrey just three minutes after take-off. Staines is just five miles from London Heathrow.

All 118 people on board were killed, and to date remains the deadliest accident in British aviation history. It narrowly missed a main road, which would have caused more casualties.

A public inquiry principally was commissioned, where the captain of the plane was largely blamed for failing to maintain airspeed or correctly configuring high-lift devices. As a result of the inquiry, mandatory installation of cockpit voice recorders in British-registered airliners was implemented.