Every summer in the seas off Alaska humpback whales, sea lions and killer whales depend on an explosion of plant life, the plankton bloom. It transforms these seas into the richest on Earth. But will these animals survive to enjoy the great feast? The summer sun sparks the growth of phytoplankton, microscopic floating plants which can bloom in such vast numbers that they eclipse even the Amazon rainforest in sheer abundance of plant life. Remarkably, it is these minute plants that are the basis of all life here. But both whales and sea lions have obstacles to overcome before they can enjoy the feast. Humpback whales migrate 3,000 miles from Hawaii, and during their 3 month voyage lose a third of their body weight. In a heart-rending scene a mother sea lion loses her pup in a violent summer storm, while another dramatic sequence shows a group of killer whales working together to kill a huge male sea lion.
In late summer the plankton bloom is at its height. Vast shoals of herring gather to feed on it, diving birds round the fish up into a bait ball and then a humpback whale roars in to scoop up the entire ball of herring in one huge mouthful. When a dozen whales work together they employ the ultimate method of co-operative fishing - bubble net feeding. One whale blows a ring of bubbles to engulf the fish and then they charge in as one. Filmed from the surface, underwater and, for the first time, from the air, we reveal how these giant hunters can catch a tonne of fish every day.

Mars is filled with mysteries, Volcanoes 77 000 feet tall, Huge canyons, 3000 miles across and 6 miles deep, all kinds of interesting features. Awaiting you is some of the greatest scenery in our Solar System, on a world where water once ruled, then vanished into thin air. Where lost microbe empires may still survive underground. We've seen the postcards, and we do wish we were there.

Cicero is finally undone by his duplicity in the form of Titus Pullo, acting upon Octavian's request to assassinate all supporters of Brutus in Rome. Pullo and Vorenus enjoy a happy if counterfeit outing with their families in the countryside to hide their assassin mission.
Vorena the Elder's dangerous dalliance with one of Mimeo's men continues, and the torrid affair between Octavia and Agrippa escalates. Atia's casual cruelty to ask for the assassination of people she doesn't like results in complete disaster for Octavia's friend Jocasta.

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.

Ewan and Charley swap their e-Harley Davidsons for plane first and follow it up with a journey by ship to Panama. McGregor's bike needs some repairs and will be fixed by the time they reach Costa Rica. The ship they travel in with the bikes looks like a beaten-down vessel that raises genuine concerns about making the journey in one piece. The boat crew looks sharp and proactive while trying to make the show crew's journey as comfortable and safe as possible. The episode also introduces Nuqui, one of the wettest regions in the world where the ship quickly makes a pitstop to fuel up on essential supplies.

Travel writer Simon Reeve embarks upon two long-distance journeys across Turkey, exploring this dramatic and beautiful country that now finds itself at the centre of world events. In this programme, he visits Istanbul and the beaches and crystal clear waters of the Aegean Sea, before ending up at the war-torn border with Syria.
In the region thought to have been the origin of the first vineyards, Simon meets a producer now trying to sell wine in a Muslim country with an increasingly conservative government. In Istanbul, he meets some of the people shaping modern Turkey, from loyal supporters of the nation's controversial and authoritarian president to the master builder constructing one of the world's largest mosques and the notorious billionaire cashing in on a Turkish property boom.
Along Turkey's famous Turquoise Coast, Simon has a taste of luxury at the country's most expensive hotel, but discovers an industry on its knees as war in Syria and deadly terror attacks keep millions of holidaymakers away.