Questions about the disgraced financier Jeffrey Epstein have dogged prominent figures ever since the child sex offender died in a Manhattan jail cell in 2019.
In recent months, US President Donald Trump has attempted to quell growing questions about his ties with Epstein.
But now the saga has crossed the Atlantic, dragging down the UK's ambassador in Washington DC, Peter Mandelson.
The latest revelations have not only cost Lord Mandelson his job, but also further wounded Keir Starmer's embattled British government.
Here's how we got here.
Who is Lord Mandelson?
Lord Mandelson was, until Thursday morning local time, the United Kingdom's ambassador to the United States.
He was appointed to the UK's top diplomatic post in Washington DC in February, tasked with sweet-talking US President Donald Trump.
Before that, he had served as a politician and minister in previous British Labour governments and a so-called "spin doctor" for the party.
He is also considered the architect of former prime minister Tony Blair's landslide election win in 1997, which ended 23 years of Conservative Party rule.
What are his links to Epstein?
That Lord Mandelson knew the convicted paedophile had previously been public knowledge, but new details released over the past week shed new light on just how close the pair may have been.
When a British newspaper asked him about them in February, the former political advisor lashed out.
"I’m not going to go into this. It's [a Financial Times] obsession and frankly you can all f--k off. OK?"
But in a release on Wednesday by the US House Oversight Committee — the same disclosure that unearthed a birthday note allegedly written to Epstein by Donald Trump — Lord Mandelson was quoted as referring to the disgraced financier as his "best pal".
It came a day after the British Telegraph newspaper revealed that, when Lord Mandelson was business secretary in 2010, Epstein had helped broker the 1 billion pound ($2 billion) sale of a UK taxpayer-owned banking business.
This was said to have taken place after Epstein first admitted child sex offences in 2008.
But there was more to come.
On Thursday, email correspondence dating from 2008 between Lord Mandelson and Epstein dropped, suggesting the sweet-talking British advisor held doubts about Epstein's paedophilia conviction.
"I think the world of you and I feel hopeless and furious about what has happened," Lord Mandelson wrote.
"Your friends stay with you and love you," he said in the emails seen by British media.
How has he and the UK government reacted?
On Wednesday, faced with the birthday book revelations, Lord Mandelson gave an interview to the Sun newspaper in which he said he regretted "very much that I fell for [Epstein's] lies".
As the links between Lord Mandelson and Epstein slowly began to emerge, Mr Starmer's opponents sought to inflict maximum damage.
The prime minister faced humiliation in parliament as the leader of the Conservative Party, Kemi Badenoch, put the issue front-and-centre.
"Does the prime minister have full confidence in Peter Mandelson?," Ms Badenoch asked.
Mr Starmer replied that he did, only to remove Lord Mandelson 24 hours later when the further emails in which his ambassador had questioned Epstein's conviction came to light.
A spokesperson for Mr Starmer told reporters that after reviewing the new information, the prime minister took "prompt and decisive action" and found some of the emails "reprehensible".
Where does this leave Keir Starmer's government?
The timing is awkward, with the year-old Labour government experiencing a slide in popularity while the right-wing populist Reform UK has been surging in the polls.
Only last week, Mr Starmer's deputy Angela Rayner, who also served as housing minister, resigned after failing to pay enough stamp duty on a house she owned.
And the US ambassador's ejection from his post also comes ahead of Mr Trump's visit to London next week.
Lord Mandelson's resignation over his links to the disgraced financier is particularly touchy, given the US president himself has also been facing a firestorm of his own over his alleged links to Epstein.
Questions have also begun swirling about what the prime minister, and his Downing Street staff, knew about Lord Mandelson's relationship with Epstein before he was appointed, with some reports suggesting security services issued warnings which were ignored.
