Between 1940 and 1943, a group of Polish diplomats in Switzerland engaged in a wholly remarkable - and until now, completely unknown - humanitarian operation. In concert with Jewish activists, they masterminded a systematic programme of forging passports and identity documents for Latin American countries, which were then smuggled into German-occupied Europe to save the lives of thousands of Jews facing extermination in the Holocaust.

While the Nazis unleashed their murderous fury, they retained a strange legalism that respected the citizens and passport holders of neutral countries. At first, these Jews were interned, in relative comfort, to be exchanged for German citizens held in these countries. Yet when it became obvious that the Latin American states were unwilling to honour these illegally issued documents, the 'Exchange Jews' gradually lost the protection that had saved them from the death camps.

With the international community failing to act, the operation was one of the largest actions to aid Jews of the entire war. The Forgers tells this extraordinary story for the first time. We follow the desperate bids of Jews to obtain these life-saving documents; we witness their painful uncertainty over whether they will offer the desired protection, as the Nazi death machine draws ever closer. And we witness the quiet heroism of a group of ordinary men who decided to do something rather than nothing and saved thousands of lives.