Terry Strada joins a lawsuit on behalf of 9/11 families, while Special Agent Danny Gonzalez and the FBI continue their investigation in secret. A BBC News Long Form Audio production.

Inside Britain's most secure interrogation room, Detective Constable David Campbell of Scotland Yard's anti-terror branch has just seven days to question the hijackers’ neighbour from San Diego. A BBC News Long Form Audio production.

After 9/11, FBI Special Agent Danny Gonzalez is chasing leads in San Diego, where two of the hijackers once lived. But another name keeps coming up. A BBC News Long Form Audio production.

With the phone to her ear and her eyes on the TV, Terry Strada is unable to comprehend how her life is about to change. Her husband is on the 104th floor of the North Tower of the World Trade Center and their four-year-old is supposed to start nursery school. A BBC News Long Form Audio production.

In early 2000, two young Saudis arrive in San Diego. They had never been to America, speak almost no English, and have no idea how to open a bank account or rent a flat. But one Arabic-speaking neighbour offers help, putting his name on the lease to secure their tenancy. A BBC News Long Form Audio production.

Twenty-five years on from the deadliest terror attack in history, BBC investigative journalist Jane McMullen asks why thousands of grieving families are still fighting for answers.In early 2000, two young Saudis arrived in San Diego. They had never been to America, spoke almost no English, and had no idea how to open a bank account or rent a flat. Within weeks they had done all of it. Twenty months later they hijacked a plane and crashed it into the Pentagon.Jane McMullen investigates a man who helped two of the hijackers – and reveals a story that the US and Saudi governments have fought to keep secret.A BBC News Long Form Audio production.

Despite a global investigation Megrahi’s conviction, and the failed appeals that followed, remain tainted- for some- by doubt and conspiracy theory. After almost four decades, a new Lockerbie trial. Abu Agila Masud is due to go on trial in August. He denies any involvement and says a video confession he made in 2011 was forced. Will the new trial finally put an end to it all?Myles Bonnar revisits relatives of the victims and investigators, as new evidence challenges long held beliefs.Lockerbie is produced by Caitlin Smith Additional production by Rob Wilson Sound design by Eloise Whitmore Story consultants are Innes Bowen, Jack Kibble White and Graham Russell Fact checking by Faisal Qureshi Research by Rachael O’Neill and Callum McCulloch-Nowlan Original development by Sally Greig Lockwood Executive Producer: Gillian Wheelan BBC Scotland commissioners: Heather Kane Darling and Victoria Easton-Riley For BBC Radio 4, the commissioning executive is Tracy Williams, and commissioning editor is Dan Clarke. Music by Callan Marchetti

Secret documents are recovered from the wreckage of Libyan intelligence agency. Myles Bonnar is given access to copies of secret Libyan files which raise fresh questions about Megrahi and his alleged co-conspirators. These documents have been dubbed the Senussi Files, after Abdullah Senussi – head of intelligence in Libya and Colonel Gaddafi’s brother-in-law. The files were found in Tripoli, in the rubble of the Libyan intelligence agency, the JSO (or ESO) destroyed by Nato bombs following the 2011 Arab Spring uprising. If verified, it links Megrahi, and others, to the Pan Am explosion, and raises new questions about the case.Lockerbie is produced by Caitlin Smith Additional production by Rob Wilson Sound design by Eloise Whitmore Story consultants are Innes Bowen, Jack Kibble White and Graham Russell Fact checking by Faisal Qureshi Research by Rachael O’Neill and Callum McCulloch-Nowlan Executive Producer: Gillian Wheelan Original development by Sally Greig Lockwood BBC Scotland commissioners: Heather Kane Darling and Victoria Easton-Riley For BBC Radio 4, the commissioning executive is Tracy Williams, and commissioning editor is Dan Clarke. Music by Callan Marchetti

Secret agent or fantasist? Jim Swire first met David BenAryeah at a gathering of the Lockerbie relatives in 1989. BenAryeah soon began passing him secret files from classified sources. So where did he get this information from and who was BenAryeah really? It’s not just BenAryeah who emerged as a mysterious figure in this case, there’s another mysterious character Myles wants to find out more about. Was Abdul Majid Giaka, aka Puzzle Piece, a double agent or a fantasist? Myles manages to get hold of secret cables between Giaka and his CIA handler which sheds fresh light on what Giaka really knew.Lockerbie is produced by Caitlin Smith Additional production by Rob Wilson Sound design by Eloise Whitmore Story consultants are Innes Bowen, Jack Kibble White and Graham Russell Fact checking by Faisal Qureshi Research by Rachael O’Neill and Callum McCulloch-Nowlan Original development by Sally Greig Lockwood Executive Producer: Gillian Wheelan BBC Scotland commissioners: Heather Kane Darling and Victoria Easton-Riley For BBC Radio 4, the commissioning executive is Tracy Williams, and commissioning editor is Dan Clarke. Music by Callan Marchetti

A grieving father is convinced the police investigation into Lockerbie got it wrong. Myles Bonnar speaks with Jim Swire, whose daughter Flora died in the explosion. He tells Myles he believes the real culprit is Iran. Jim has always been outspoken about his theories. He claims his rising profile attracted unwanted attention from intelligence agencies, both in Britain and abroad. But what did they want with him? Jim tells Myles about David BenAryeah – a supporter of the Lockerbie group who Jim believed was a member of Israeli intelligence agency, Mossad. But Myles knows him as someone very different. Jim Swire’s not the only one who has doubts about who bombed the plane and why. The Lockerbie case has long been at the centre of a complex web of conspiracy. Myles speaks with a member of Abdelbaset al-Megrahi’s appeal team who tell him what they believe really happened in the months leading up to the Pan Am explosion.Lockerbie is produced by Caitlin Smith Additional production by Rob Wilson Sound design by Eloise Whitmore Story consultants are Innes Bowen, Jack Kibble White and Graham Russell Fact checking by Faisal Qureshi Research by Rachael O’Neill and Callum McCulloch-Nowlan Original development by Sally Greig Lockwood Executive Producer: Gillian Wheelan BBC Scotland commissioners: Heather Kane Darling and Victoria Easton-Riley For BBC Radio 4, the commissioning executive is Tracy Williams, and commissioning editor is Dan Clarke. Music by Callan Marchetti