Twenty years ago, fourteen-year-old Valerie rushed off for lunch with her boyfriend instead of properly putting away a packet of balloons, and her little brother choked to death on his third birthday. In response, Valerie locked down every aspect of her life so she could never lose control like that again, and she's still doing that today. So when her sister Gloria is found comatose after an apparently random attack, Valerie is desperate to do something, anything, to save her only remaining sibling. But as a financial controller for a "nothing bigger than a size six" fashion designer, she has no medical background and no idea of how to help. But she has to find a way. Since Gloria has always wanted to be a size zero, Valerie hits on food as the answer: by eating less, she will lose the weight Gloria now can't and somehow save her sister that way. But when "eating less" turns into a frantic starvation diet to reach size zero before Gloria dies, will Valerie's self control save her sister or destroy her own life?