The Quail Walkers' final step into their Ulster-Scots history starts in Toronto where Gavin Andrews finally reveals to Desmond and Caroline the identity of a famous ancestor. He was at the centre of a Victorian maritime mystery and his story is the stuff of legend. The Quail boys have learnt about him at school but had no idea there was a family connection.

Dad Phil, Noah and Fionn travel to London to test their sea legs while Caroline and Desmond head to Ottawa to meet the experts working to unravel the mystery surrounding their ancestor who went missing in the arctic archipelago.