This 17th children’s novel by Julia Green, who has coached a host of writers to success on Bath Spa University’s creative-writing course, feels timeless, even though it takes place after environmental disaster has returned existence to a struggle to live simply off the land. The setting is a nameless island, a place of border guards and intrusive authorities. Rebellious Bonnie, who lives with her increasingly frail grandfather, finds a dilapidated old rowing boat, and then a boy in need of help, who is a refugee from the sea. Together they plan an escape, driven by hope. A tender strand of revelations about Bonnie’s lost mother, affecting characterisation and a gentle, rocking prose carry us through this illuminating story.