The Okavango is one of the most diverse habitats on earth -- a kingdom like no other. Here, the arrival and disappearance of sweet fresh water alters the balance of life for so many. The flood is a sanctuary and a trap, giving and taking life in equal measure. Above and below the water, never ending battles of wits and survival play out. This is a place of spectacular natural dramas where the fortunes of tens of thousands of animals each year are controlled by one ruler - The Great Flood.