Kimberley and Gary's great grandad can magically transport them into the past. Grandad's magic extends to allowing he and the children, even in modern dress, to be accepted as guests of the people they visit.
Grandad Albert takes Kim and Gary back to a breakfast time when he was a lad, where the porridge has been cooking on the range all night and bacon is only served for the man of the house.
Grandad Albert takes the kids back to see how people travelled about when there wasn't any cars.
Gary doesn't want to have a bath, Grandad Albert tells him all about when he was young, his family didn't even have a bathroom.