There’s a hidden danger lurking in every home. Meet the two mothers who’ve achieved a world first to protect our children. Button batteries lurk inside many seemingly harmless household items from musical birthday cards to remote controls to stuffed toys. To an adult they're just a battery but to a small child their shiny appearance can be fascinating and potentially lethal. When Andrea Shoesmith and Allison Rees lost their children to button battery accidents, they channelled their grief into lobbying to make the industry more accountable. What they've achieved is remarkable and their passion for change will ultimately protect children around the country.