Belfast, 1944: American soldier James McCann meets the beautiful and impetuous Rose Rafferty. They fall in love, but their romance is forbidden - and war separates them. Boston, present day: James's children are celebrating his life when they find a wartime letter that changes everything. They have a half-sister, born in an Irish mother and baby home, stolen by the nuns and exported to the US. Their search for justice will cross oceans and generations. It will uncover secrets and lies, revealing the abuse of the most innocent in society by the most powerful. It will pit them against Church and State and shine a light into the darkest corners of Irish history.