A seven-part docuseries about the unsolved murder of a nun and the horrific secrets and pain that linger nearly five decades after the death of her.
In the first episode, two former students launch a dogged investigation into the cold case of Sister Catherine Cesnik, who was slain in Baltimore in 1969.

Sir David Attenborough chooses his favorite recordings from the natural world --from the song of the largest lemur to the song of the humpback whale to the song of the lyrebird-- that have revolutionized our understanding of song. The science of song had been transformed by Charles Darwin’s theory of sexual selection: singing is dangerous as it reveals the singer’s location to predators, but it also offers the male a huge reward, the chance to attract a female and pass on genes to the next generation. Today, new science in the field of birdsong is transforming those long-held ideas.
Scientists are discovering that, in fact, in the majority of all songbird species, females sing - and it is only now they are being properly heard. Through this revelation and others, we can understand that animal songs are marvellous examples of the spectacular survival strategies that species have developed.

A team of intrepid palaeontologists recently discovered a lost world of dinosaurs in the unlikeliest of places — deep in the dark, snowy wilds of northern Alaska. Surprisingly, new findings indicates that dinosaurs thrived year-round and raised their young in frigid and dark conditions in the far north of the Arctic Circle.
Rappelling down giant ice cliffs bordering the Colville River, the team wields chainsaws to extract fossils frozen into the permafrost. Newly found dinosaur tracks indicates that a wide variety of species once flourished there, including herds of duck-bills, horned herbivores, pterosaurs, a new type of velociraptor, and northern relatives of T-rex.

Scientists and engineers fight to save Notre Dame Cathedral after the 2019 fire. When the roof of Notre Dame Cathedral erupted in flames in April of 2019, firefighters battled for nine gruelling hours to save the historic landmark. Still, Paris came alarmingly close to losing more than 800 years of history. Now engineers are in a different race against time: to rebuild the roof and secure the medieval structure of Notre Dame. Underneath the charred scaffolding and vaulted ceilings of the cathedral, scientists study the components of Notre Dame’s iconic structure to puzzle out how best to repair it.

On the trail of tiger sharks in the Pacific, Will Smith explores the power of smell. Sharks have a sense of smell that's hundreds of times more potent and accurate than that of humans. An enormous part of their brain is dedicated to smelling, to finding their way through the vast expanse of the ocean.

In the third episode, Will Smith crosses the Serengeti to catch one of the greatest events of nature. "An image, one and a half million wildebeests on the plains of Africa in the most dramatic migration on Earth, has stayed with me since around thirty years ago I picked up a National Geographic Magazine and saw it. And finally, I'm here to see it."