A fortnight ago in the opulent Savoy Hotel in London, Theresa May gave a hint of the dramatic rescue just miles away of three women from their captors.
The Home Secretary told an awards ceremony: "We're sitting here in these beautiful surroundings, having had a wonderful meal.
"But remember there are men, women and children in our country who are living lives of servitude and misery - probably some of them not too far away from where we are today."
She spoke of her determination to tackle the "long engrained injustice" of modern-day slavery, singling it out as a priority for the Home Office.
Next month Mrs May will publish a draft Modern Slavery Bill that will bring together measures to combat human trafficking and the activities of gangmasters. The aim is to get the Bill on the statute book within a year.
Under its measures, the most serious offenders will face life in jail, while other traffickers would banned from owning companies, working with children or young women or visiting certain premises.
It will create a modern slavery commissioner whose job will be to hold government departments and agencies such as the police to account if they fail to tackle the problem. It will also improve training for officials to recognise when people are being against their will.
A Home Office minister today spoke of his fears that thousands of vulnerable people could be working unpaid in agriculture, industry, prostitution and domestic service in Britain.
James Brokenshire warned that criminal networks were trafficking victims from across the world, many of whom did not even realise they were being held in Britain.
He said: "It is difficult to genuinely quantify the problem, though one organisation has said the number [of slaves in the UK] is as high as 6,000.
"If you see something you think is suspicious, that doesn't quite add up, if you have natural concerns that something does not feel quite right, then report it to the police and they will investigate."
David Cameron's official spokesman said the Prime Minister viewed the case as "utterly appalling".
He said: "The importance of this issue and the importance of ensuring that, where it is occurring, it is brought into the open is exactly why the Government is taking through the House the modern-day Slavery Bill."
Video: 'Psychological' control