Pyjamas are just pyjamas. Right? Not when they're Cosmic Pyjamas! Something strange has happened to Rosie and her brothers! Rosie's new pyjamas have led them to a dangerous discovery...Doctor Starkly-Bonkers has invented the Doombuster and history is all muddled up - and now the machine has been stolen! Can Rosie and the boys beat the Pharaohs and dinosaurs and will rice pudding really stop the Vikings?