In the oxbow lakes of Zambia’s Luangwa River, giants lurk just below the surface. Carpeted by Nile cabbage, these overgrown oases are a haven for hippos. Here, they want for nothing… but a river cannot always be in flood. In the dry season, the Luangwa transforms from lush paradise, to boneyard. During these harsh months, the largest concentration of hippos on Earth must wrestle for space in a rapidly shrinking river. We uncover the mysteries of these iconic species.