The images of brothers Tamerlan and Dzhokhar Tsarnaev are released to the public setting off a violent chain of events. Meanwhile, clues from their past tell a complicated story - how was the radicalization of the ethnically Chechen brothers and the existence of potential collaborators. The post-9/11 biases played a role in the investigation.

When he killed Mehmed’s messengers, it was a message from Vlad Dracula that he would not pay his yearly dues anymore and it was clear that Vlad wanted a war against the Otoman Empire. Mehmed II sends Mara to coax Hungarian King Matthias Corvinus into an alliance. Vlad Dracula’s army was less than 30,000 men, but he invaded Bulgaria and started killing Mehmed’s men in 1462. He stole the Ottomans’ uniforms for his further attacks on the empire. Vlad also destroyed many ports that were under Sultan Mehmed II on the Danube.
Mehmed had to cross the Danube in order to reach the capital city of Târgoviște and defeat Vlad. The sultan faced the challenge of transporting 100,000 men across the river. Along with men, he had to transport cannons and horses too. The first unit to cross the river Danube included Mahmud Pasha, who was the most trusted man of Mehmed II. An epic battle along the Danube River looms, and Vlad has the upper hand.

Journey to secret worlds where lives are wrapped in unexpected of ways. The fifth episode of the series takes viewers into the fascinating world of forests, revealing their hidden complexities and the intricate relationships within. Initially perceived as tranquil, forests are in fact bustling with life and intricate ecological interactions. The episode showcases various species, each with its unique lifestyle and survival strategies. Highlights include the Oriental pied hornbills in Borneo, whose extraordinary nesting rituals and partner dynamics are captivating.
The Amazon rainforest is explored, introducing the peculiar treehoppers and their unique communication methods, vital for survival amidst numerous predators like ants and assassin bugs. The episode also delves into the intelligent and cooperative hunting techniques of dholes in the forests of India. The narrative takes a turn to China, focusing on the visually stunning courtship displays of Temminck's tragopans and golden pheasants. In the temperate rainforests of Western Canada, the rare spirit bear and its unique relationship with its habitat are examined.
The episode concludes with an insightful look at the impact of human activity on forests and their inhabitants, particularly focusing on chimpanzees in Uganda, whose survival is increasingly intertwined with human expansion.

Following their identification, the Tsarnaev brothers killed an MIT policeman, then kidnapped a man in his car. They had a shootout with the police in nearby Watertown, during which two officers were severely injured (one of whom, Dennis Simmonds, died a year later). Tamerlan was shot several times, and his brother Dzhokhar ran him over while escaping in the stolen car. Tamerlan died soon after.
An unprecedented manhunt for Dzhokhar ensued, with thousands of law enforcement officers searching a 20-block area of Watertown. Residents of Watertown and surrounding communities were asked to stay indoors, and the transportation system and most businesses and public places closed. After a Watertown resident discovered him hiding in a boat in his backyard, Dzhokhar Tsarnaev is cornered into an intense standoff. As officials navigate remaining questions and suspicions, the city emerges Boston Strong.

The final episode begins with a description of the extreme cold conditions that characterized the beginning of the Holocene period, and how species like the bison and the wolf adapted to survive in these hostile environments. We will witness the majesty of the woolly mammoth and the fierce cave lion, with a vivid reconstruction of their struggles for survival. We'll see the impact of climate change during this period, from the expansion of the deserts to the transformation of the tropical rainforests of Africa into grasslands, deeply affecting primates and other animals. It highlights how these changes forced primates to adapt to life on the ground, facing new challenges and predators.
A crucial turn occurred with the emergence of humans as dominant predators and their influence on the extinction of large mammals. The documentary describes humanity's transition from hunter-gatherers to farmers, a change that radically altered the landscape and biodiversity of the planet. Finally, it poses a reflection on the current challenges of climate change and the sixth mass extinction, inviting viewers to consider humanity's crucial role in shaping the future of the Earth.

Explore the breathtaking extremes of our planet in this captivating episode. Journey through the vast Hang Son Doong cave in Vietnam, the largest on Earth. Witness the resilience of life in harsh conditions, marvel at the adaptation strategies of species like the blind cave fish and the enduring Arctic wolf pack. In the Arctic, observe the strategic hunt of wolves preying on musk oxen, a dance as old as the Ice Age. In the French Alps, the struggle for mating among common frogs unfolds, showcasing the urgency and challenges faced by cold-blooded animals. Witness the social dynamics of Barbary macaques in the cedar forests of the Atlas Mountains, where survival hinges on social bonds. The forests of Mexico, home to millions of monarch butterflies that huddle for warmth, illustrates the fragility and beauty of nature.
Discover how fire shapes ecosystems in South Africa's fynbos and Northern Australia, crucial for the survival of species like the golden-shouldered parrot. The documentary poignantly addresses the impact of changing climates and human intervention on wildlife, from the endangered elephants of Amboseli, Kenya, to the secretive snow leopards of the Gobi Desert. This episode offers a profound glimpse into the extraordinary adaptations and challenges faced by wildlife across the globe, reminding us of the delicate balance and beauty of life on Earth.