Ellie Shrapton and her family live in a world controlled by rules. One such rule is that all forms of sugar have been banned in every country but one. The Shraptons make due until one day Ellie's husband casually mentions wanting a birthday cake. Ellie can't get that thought off her mind, so she procures ingredients and starts baking. Once she has a taste of sweet freedom, there's no going back to life as it was, even if it puts Ellie and those she loves in danger.