Covering US politics from Washington in recent years there has been one, overarching story that has dominated the narrative - Donald Trump and allegations of election interference. The issue sat at the heart of special counsel Robert Mueller’s probe into how the Kremlin interfered in the 2016 race and whether there were connections to the Trump campaign. It also underpinned the scandal that triggered Mr Trump’s impeachment - his push to get Ukraine to investigate his political rival and possible 2020 challenger Joe Biden. As another presidential election on November 3 approaches, there is value in looking back to properly understand what happened before 2016. In particular, throughout the Trump-Russia saga there were threads that repeatedly ran through the UK but were never fully explored. There was the pair of London meetings, one in a West London wine bar over gin and tonics, that proved the trigger for the FBI to launch their Russia investigation. There was the former MI6 agent who uncovered shocking allegations about Trump-Kremlin links - always denied - and documented them in memos now dubbed "the dossier". Or the Cambridge University don turned FBI informant who approached and recorded members of Mr Trump’s campaign, probing the Russia angle. Or the posh London apartment, just round the corner from Harrods, from where a computer geek managed to upend the election by publishing private Democratic emails. In an attempt to understand what really happened, the Telegraph spent the last year tracking down people who saw the events firsthand and asking what they knew. The result is a six-episode podcast called Crossfire - the FBI investigation itself was code-named Crossfire Hurricane - which unpacks it all, piece by piece. The stories reveal something about the nature of Trump campaigns - the characters they attract, the pressure they operate under, the norms they are apparently willing to break. Those insights, with Mr Trump straining every sinew to win re-election this year, are as relevant today as they have ever been. Subscribe to Crossfire for free on Apple Podcasts, Google Podcasts, Spotify, Pocket Casts or search "Crossfire" on your podcast app.