For nearly a thousand years, the Underkin have lived beneath the earth, hidden from a world that forgot they ever existed. When a fire destroys the house above their ancient refuge, smoke invades the depths and forces them into the light. Emerging onto a windswept coast they no longer recognise, the Underkin find a world transformed by centuries of change. Met with wonder by some, suspicion by others, they must navigate an unfamiliar land while guarding the secrets of their past. But as old fears awaken and tensions rise, the Underkin discover that surviving the surface may be more dangerous than anything they left behind underground.