a female chacma baboon goes about business in Zimbabwe's Mana Pools National Park

It sounds like a blockbuster political thriller, steeped in intrigue and sex, with echoes of Shakespeare. Life becomes a nightmare for a child of the ruling family when his father is deposed, his mother's affections commandeered, his brother murdered. His own survival hangs by a thread.

But it's not fiction. It's not even human. It is the true story of the social chaos that sweeps a society of baboons in Zimbabwe when its male leader is overthrown by an interloper.

The story takes place along the banks of Africa's Zambezi River, which forms the border separating Zimbabwe from Zambia before crossing Mozambique and emptying into the Indian Ocean.

On the southern bank, in Zimbabwe, cameras follow a troop of some 40 chacma baboons, with a special focus on twin males born to the reigning male and female of the troop. Although the entire Zambezi troop faces daunting challenges - including months of drought and threats from predators - the twins' "royal" parentage would seem to give them an advantage in terms of their prospects for survival.

Watch a preview and find out more at pbs.org

Watch it Saturday, December 13th at 6:00 p.m. on PBS-World