On February 5th 2004 23 Chinese cockle-pickers drowned in Morecambe Bay, this is the story of the people behind the tragedy and the families in China still paying off their debts. When a young girl, Ai Qin, pays $25,000 to be smuggled into the UK, in order to support her family back in China, she becomes another one of 3 million migrant workers that have become the bedrock of our economy. Nick Broomfield's thoughtful, angry film provides a striking insight into the secret society upon which we rely but fail to acknowledge.