The German army launched Operation Barbarossa, the invasion of the East, with supreme confidence in its own superiority. High Command was sure that victory would come as quickly and as easily as in France. At the onset, the troops advanced rapidly and the Panzer forces under General Guderian were unbeatable. There were, however, far more casualties and more wear-and-tear on equipment than anticipated. The invading force got bogged down short of Moscow and the withdrawal from there was a severe psychological blow to the men. When an extremely severe winter set in, morale sank further. The soldiers were not equipped for such low temperatures and their guns and machinery could not cope. Hitler ordered his troops to stand firm.

The world's deserts are lands of extremes that force animals to come up with ingenious ways of coping with hostile conditions, giving rise to the most incredible survival stories on earth. A pride of desert lions are so hungry they risk hunting a giraffe several times their size, while male sandgrouse fly 120 miles each day to the nearest waterhole and dice with death to collect water for their chicks. Filmed for the first time, a tiny bat does battle with one of the world's deadliest scorpions, and in Madagascar, a locust swarm of biblical proportions is seen as never before.

The third episode is devoted to the ways in which plants reproduce. Pollen and a stigma are the two components needed for fertilisation. Most plants carry both these within their flowers and rely on animals to transport the pollen from one to the stigma of another. To do this, they attract their couriers with colour, scent and nectar. It isn't just birds that help pollination: some mammals and reptiles also do so. However, it is mostly insects that are recruited to carry out the task. To ensure that pollen is not wasted by being delivered to the wrong flower, some species of plant have developed exclusive relationships with their visitors, and the gentian and its attendant carpenter bees is one example. Since pollen can be expensive to produce in terms of calories, some plants, such as orchids, ration it by means of pollinia and a strategically placed landing platform. Other orchids offer no reward for pollination, but instead mislead their guests by mimicking their markings and aroma, thus enticing males to 'mate' with them (Pseudocopulation). The most extreme fertilisation method is one of imprisonment, and one plant that uses it is the dead horse arum. It is often found near gull colonies, and mimics the appearance and smell of rotting flesh. Blow-flies are attracted to it, and are forced to stay the night before being allowed to depart in the morning, laden with pollen. Finally, Attenborough introduces the world's largest inflorescence: that of the titan arum.

Atheist and scientist Richard Dawkins visits England, America and Israel interveiwing prominant people of faith; Islamic, Hasidic Jews, and the new Christian sects popping up throughout the world, and expressing his view of the extent to which this fanaticism has degraded our civilisation, and will continue to degrade it. "The God Delusion" explores the unproven beliefs that are treated as factual by many religions and the extremes to which some followers have taken them. Dawkins opens the programme by describing the "would-be murderers ... who want to kill you and me, and themselves, because they're motivated by what they think is the highest ideal." Dawkins argues that "the process of non-thinking called faith" is not a way of understanding the world, but instead stands in fundamental opposition to modern science and the scientific method, and is divisive and dangerous.

Jupiter is a turbulent world of monster magnetic fields and endless mega storms. Generations of astronomers have attempted to solve the mysteries of Jupiter, the most fierce and extreme planet in the Solar System. And now, NASA's Juno probe is revealing new evidence that could unlock the secrets of why this planet is so strange. With Juno, we're able to see Jupiter from the inside out and reach deep into its core to reveal how it grew.

Inside the world-renowned physics laboratory Fermilab, a team of scientists are constructing an audacious experiment to hunt for a mysterious new ‘ghost’ neutrino. If they find it, this could transform our understanding of the nature and fabric of our universe. The problem is, these tiny particles are almost impossible to detect.
Elsewhere, physicists conduct experiments in some of the most extreme environments on the planet: from deep mine shafts in South Dakota to vast ice fields at the South Pole. In these unlikely places supersized neutrino detectors hope to unlock the universe’s deepest secrets. Could neutrinos overturn the most precise theory of particle physics that humans have ever written down? Could they even be a link to a hidden realm of new particles that permeate the cosmos – so called dark matter? Scientists at Fermilab are edging towards the truth.