Julian Richards investigates the impact of the Vikings in Britain. This edition focuses on the archaeological trail left by the Vikings as they travelled from Norway along the sea road to Dublin. Settlements, a boat burial and evidence of trading have been discovered on the Scottish isles, and silver hoards found in Ireland suggest that Dublin was not only wealthy and important, but also a centre for trade in slaves.

Professor Robert Bartlett explores the impact of the Norman conquest of Britain and Ireland. Bartlett shows how William the Conqueror imposed a new aristocracy, savagely cut down opposition and built scores of castles and cathedrals to intimidate and control. He also commissioned the Domesday Book, the greatest national survey of England that had ever been attempted. England adapted to its new masters and both the language and culture were transformed as the Normans and the English intermarried. Bartlett shows how the political and cultural landscape of Scotland, Wales and Ireland were also forged by the Normans and argues that the Normans created the blueprint for colonialism in the modern world.

Episode three explores the mind of one of the most fanatical of all Nazis and the insight that gives into the psychology of dictatorship. Hess is brought to Nuremberg from the UK where he had flown 4 years earlier much to the bemusement of the British. Overy explains that they must have quickly realised he was not normal. In the intervening time Hess’s mental state has further deteriorated and when interviewed by Chief Interrogator Colonel John Amen proclaims amnesia. Chief Interpreter Richard Sonnenfeldt explains that they brought in Göring to confront Hess but that he too failed to make an impression.
Psychopathologist Prof. Edgar Jones proposes Hess’s behaviour patterns may be his way of escaping reality as he is forced to face the extent of the atrocities and choose between accepting his part of the blame or forsaking his Führer. However, as history Professor Robert Gellatel explains it is difficult to construct a case against Hess as he was imprisoned in England when the worst of the atrocities were carried out so British Prosecutor Mervyn Griffith-Jones must argue a conspiracy charge linking the pre-1939 persecutions to the post-1939 atrocities and a crimes against peace charge proving the flight to Scotland was merely a ruse.

Planets beyond our solar system are known to astronomers as exoplanets. They are at trillions of miles from Earth and yet, it might be possible to detect a faint signature of life in them. From the light of the stars they orbit that passes through the atmosphere of an exoplanet, it is possible to capture the chemical fingerprint of the elements in that atmosphere.
The fictional world Eden is orbiting not one star, but two. The light from its twin stars powers photosynthesis, pumping more oxygen into the atmosphere than in Earth, allowing life to thrive. Grazers are constantly alert to danger, because the canopy is home to predators perfectly evolved to live among the trees. In Episode 3, another topic are fungi and the role they could play on exoplanets. Ecologist Thomas Crowther talks about the role mycelial networks play in the Rothiemurchus forest in Scotland.

Sir David Attenborough explores the incredible diversity of Britain’s woodlands, taking us on a seasonal journey through our forests, and revealing a host of spectacular animals and the hidden dramas that rule their lives.
In an ancient pine tree in the Cairngorms, two eagle chicks are on the verge of fledging their gargantuan nest. In winter in the Forest of Dean, the reintroduction of wild boar has given the robin a lifeline. As they root through the thick snow, the boar unearth the worms with their snouts, which the robins otherwise couldn't find.
Back in Scotland, a male capercaillie displays to gathering females. These birds are on the edge. With only around 500 left, they are some of the rarest and most threatened in the British Isles. In a beech woodland outside London, the deciduous trees burst to life in spring, and huge colonies of wood ants awaken and go looking for food. Also looking for sustenance is a female roe deer. With no large predators left in our woods, the deer are free to browse on new growth to the extent that they can damage the woodland itself.
In Sussex is an ancient-looking landscape, but one that has only been recreated in the past 20 years. This is the wood pasture of Knepp, created by using old grazing methods that generate a mix of scrub, open areas and ancient trees. In the Scottish Highlands, red squirrels battle it out for access to ripe pine cones at the top of a tree. It’s an acrobatic and energetic encounter, with more than a little cunning required to win the day. As the summer finally fades, we encounter a honey buzzard nest, where two chicks feast on wasp grubs, squabble between themselves and grow up before our eyes.
Autumn brings the fallow deer rut. The woods resonate with their calls, and bucks fight for supremacy. The season also brings colour, both in the leaves but also in the fungi that fruit at this time of year. The mushrooms are just a tiny part of their story, however, and we travel underground to see how the wood-wide web connects the whole forest together.

This episode takes you on an enchanting journey through the vital waterways of Britain and Ireland. From the serene reed-beds of Somerset to the bustling ecosystems of Scotland's lochs, the film unveils the intricate dance of life sustained by freshwater. Marvel at the agility of dragonflies and the aerial prowess of hobbies, witness the arduous journey of Atlantic salmon as they return to their birthplaces to spawn, and observe the fascinating life cycle of the mayfly. Discover the impact of reintroduced beavers in Scotland, creating new wetlands that buzz with life. The episode doesn't shy away from showcasing the challenges these ecosystems face, from climate change to pollution, emphasizing the delicate balance that sustains these vibrant freshwater habitats.
‘Freshwater’ is a mesmerizing ode to the streams, rivers, and lakes that are the lifeblood of the Britain and Ireland isles, supporting a diverse array of life in one of the planet's most beautiful settings.