It's 1931 and eighteen-year-old Greta is working in a laundry in Liverpool, where she lives with her widowed mother and thirteen-year-old brother Kenny. When a scruffy black and white collie follows Greta home one day, Kenny wants to keep the animal, but they can't afford to feed him. And so Greta tracks down the owner: Mungo Masters, a wealthy man who runs funfairs in three towns.

Mungo falls for Greta, though he's her mother's age, and doesn't bother to tell her that he's married already. When Mungo gives Greta and Kenny jobs at one of his fairs, it seems life is looking up. But Mungo is not good news...