Part two of two. Anthony McPartlin and Declan Donnelly embark on a journey to New York to follow the bloodlines of their mothers using DNA analysis and genealogy. There is a surprise for Dec as he finds out he has close family he never knew existed, while Ant's history takes him to the United Nations. After a whirlwind tour of the US, it's back to Ireland to investigate a family secret that Ant's family has been trying to unlock for years.