When ill health forces the Radfords' son-in-law Harley to quit work, his mood hits an all-time low as finances become tight, so Millie buys a dog to cheer him up. Meanwhile, Sue and Noel prepare to celebrate another year together with a short break in the Lake District, but an unexpected financial windfall prompts them to revise their plans.

The Radfords set out to explore their family heritage, but true to form, the ever-competitive Noel and Sue turn the journey into a challenge. With the help of historians and experts, they go head to head to see whose side of the family tree holds the biggest shocks and surprises on a journey that takes in South Wales, Bollington near Macclesfield, Manchester and France.