A secret world rich in wildlife is hidden away inside an ancient volcanic crater in Kenya's rift valley. Mighty geysers of steaming water, boiled underground by highly sulphuric volcanic activity, gush to the surface of the valley floor. The poisonous, highly alkaline water flows from the geysers into a lake called 'Bogaria', which stretches the length of the ancient caldera. This is one of the most hostile lakes in the world. Two million flamingos live around these caustic waters, while a penetratingly hot equatorial sun beats overhead. Predators abound on the shores of the poisonous lake, tempted by an abundance of prey. Unlikely predators partake: hungry baboons and opportunistic marabou storks ravage the birds. Our story follows a family of African fish eagles, which specializes in feeding on flamingo flesh at this staggeringly beautiful, yet utterly savage, 'Gate of Hell'.