In Botswana’s Okavango Delta, an ostracized lioness and her two cubs must fight alone to survive - overcoming all manner of hazard, from the raging wildfires on the Delta, to the jealousy of sister lionesses, to the marauding males who kill her mate, to the prey that becomes predator. Their only defense is to escape to Duba Island — and with that, an unknown future.   The setting for this epic tale is one of the last regions where lions can live in the wild. Faced with dwindling land and increasing pressure from hunting, lions - like our lone lioness and her cubs - are approaching the brink of extinction.