''Are you sure they're safe to eat?'' My mum looked at me, sceptically, then down at the package of fresh mussels I was holding. ''I've heard so many stories...'' Not to worry, I assured her; these babies would be safe to eat, as long as I stuck to the Golden Rule. ''The what?'' she replied, perplexed, raising her left eyebrow ever so slightly (ah mothers...) The Golden Rule, I informed her, is the idiot's guide to making mussels safe to eat. It's all very simple. Before you begin cooking the mussels, throw away all open mussels. And after you've done cooking them, throw away all the closed mussels. If you follow that rule, there is no need for an ambulance; they're safe to eat and you won't get sick.