For ten years, the hadls - humanoid creatures homo hadalis living in the depths of the planet - have not made any news of themselves. It is officially believed that they died from the deadly virus. But suddenly a wave of mysterious crimes sweeps across America - someone kidnaps children, and adults, if they are nearby, are found murdered. Everything indicates that this is the work of the people of the abyss, the hadls. Rebecca Coltrane, the mother of one of the stolen girls, gathers an army of volunteers and goes in pursuit of the kidnappers... “Underworld. Hellish Abyss is the long-awaited sequel to The Underworld. novel that topped the New York Times bestseller lists.