It's December 1963 when Billy Hopkins and his wife Laura arrive home in Manchester after five years in Africa.
The world has changed beyond recognition: it's the swinging sixties, with headlines full of the Beatles and the pill, LSD and mini skirts.
Billy's youngest son still believes in Santa Claus and while his daughter's reading Jackie, she's not even a teenager yet, so Billy's not too worried about the impact of modern society on his family.
He's more concerned about the welfare of his increasingly forgetful father and about the daily challenges he faces as a college lecturer.
When the four junior Hopkins start to choose their own, unexpected paths in life, though, Billy finds it harder than usual to see the funny side of things...