Someone has dug up the private garden in the Square and taken buckets of dirt, and Miss Angela Chesney of the Garden Committee is sure that a gang of boys from Catford Street must be to blame. Angela's sister Olivia isn't so sure. She wonders why the neighbourhood children - the 'sparrows' she sometimes watches from her window - have to be locked out of the garden: don't they have a right to enjoy the place too? But nobody has any idea what sends neighbourhood waif Lovejoy Mason and her few friends in search of 'good garden earth'. Still less do they imagine where their investigation will lead them - to a struggling restaurant, a bombed-out church, and, at the heart of it all, a hidden garden.