February, 1941. After months of bombing raids in London, twelve-year-old Olive Bradshaw and her little brother Cliff are evacuated to the Devon coast. The only person with two spare beds is Mr Ephraim, the local lighthouse keeper. But he's not used to company and he certainly doesn't want any evacuees.
Desperate to be helpful, Olive becomes his post-girl, carrying secret messages (as she likes to think of the letters) to the villagers. But Olive has a secret of her own. Her older sister Sukie...