Bob Poole joins lion scientist Paola Bouley to solve a baffling mystery: why is Gorongosa’s lion population not growing as fast as it should? After a decade of restoration efforts, there seems to be plenty of prey for the lions to eat. But their population isn’t growing. Because lions are an important keystone species, and a draw for tourists, their recovery is critical to the success of the restoration effort. By filming the lions, Poole hopes to help solve the mystery. He meets a new lion family with five young cubs, and follows their perilous journey to adulthood. The team encounters a three-legged lioness called Tripod who guides them to a potential answer to the mystery they’re trying to solve. Tripod has given Gorongosa a precious legacy — the five cubs Bob has been filming are her “grandkids”. But their lives are put in danger with the arrival of two male lions that want to expand their own lion kingdom.
Bob Poole and his sister Joyce, a renowned elephant expert, face charging elephants to gain insights into elephant behavior. Meanwhile, Mt. Gorongosa is taken over by a group of rebel soldiers, creating a tense air of uncertainty and fear in the park.
Bob and the lion team find one of the female cubs with a life-threatening wound and face a race against time to save her. Lions aren't the only ones who need help. During the war, most of the big grazers were killed for their meat. With less than 20 zebra and 100 eland, the park needs to make a tough choice to save them. A massive relocation mission is launched to bring them back. But what happened to Gorongosa when these big grazers weren't around to eat the grasses? It's these kind of mysteries that are attracting the best scientists in the world. Harvard insect expert, Piotr Naskrecki looks to the micro scale for answers and discovers a surprising hero that kept Gorongosa alive after the war.
Flying over the north section of the park, Bob Poole discovers remote rivers choked with enormous crocodiles. Estimating it to be the largest croc population in Africa, Bob brings in experts Sven Bourquin and Vince Shacks to investigate. It's not only the number of crocodiles that surprises the team, but the behavior of the reptiles as well. It's the beginning of mating season and they should be aggressively protecting their territory - but they're not. Gorongosa has other hidden worlds the scientists know nothing about. Bob joins Harvard insect expert Piotr Naskrecki and his team to explore the deep limestone gorges to the east. Rapelling down, they discover pristine forests and caves packed with new life. Bob films a ferocious battle on the micro scale - monster-sized ants slaughtering termites in the thousands. It's these hidden worlds that Piotr wants to bring into the limelight because it's the little things that truly run the world.
A new male lion bursts onto the Gorongosa scene, and a cold war for lion dominance of the floodplain begins. Joyce Poole arrives back at the park with new questions about the mysterious behavior of Gorongosa's elephants. Bob joins the rangers on a night patrol of villages suffering from crop-raiding bull elephants, and gets a taste of the danger crop raiding poses to people and elephants alike. Joyce has a breakthrough encounter with the park's aggressive elephant matriarchs, and Helena the young lioness finds herself and her young cubs trapped between two powerful rivals.
Wildlife cameraman Bob Poole returns to a transformed Gorongosa and discovers annual rains have flooded the plains and forests, turning what was a dustbowl into a water world. Exploring the park at this special time of year, Poole discovers a huge nesting colony of water birds that proves to be one of the greatest birding spectacles in Africa. All this beauty is threatened again as armed conflict between the country's two political parties flares up, jeopardizing the future of the entire park restoration project. As floodwaters recede, Bob resumes his search for the Sungue Pride cubs that went missing. After many sleepless nights, he finally meets the park's new cubs - the future of lions in Gorongosa.