If everyone knew every plant and tree

Oliver Campbell, fourteen, fanciful and funny in equal measure, struggles to unravel the knots of emotion when his little sister, Lily, falls gravely ill with a mysterious disease. Irritating and puzzling to his two older half-brothers, neglected by his self-absorbed mum and dad, and unfalleninlovewith by Poppy Teasdale, he longs to be something more than invisible.