The fifth programme explores the alliances formed between the animal and plant worlds. Attenborough dives into Australia's Great Barrier Reef and contrasts the nocturnal feeding of coral, on microscopic creatures, with its daytime diet of algae. Some acacias are protected by ants, which will defend their refuge from any predator. Besides accommodation, the guards are rewarded with nectar and, from certain species, protein for their larvae as well. Fungi feed on plants but can also provide essential nutriment to saplings (Mycorrhiza). The connection is never broken throughout a tree's life and a quarter of the sugars and starches produced in its leaves is channelled back to its fungal partners. Meanwhile, fungi that feed on dead wood leave a hollow trunk, which also benefits the tree. Orchids enjoy a similar affiliation. Lichens are the product of a relationship between fungi and a photosynthetic associate, usually algae. They are extremely slow-growing, and a graveyard is the perfect location to discover their exact longevity. Mistletoe is a hemiparasite that obtains its moisture from a host tree, while using own leaves to manufacture food. Its seeds are deposited on another by the mistletoe tyrannulet, following digestion of the fruit. The dodder (Cuscuta) is also parasitic, generally favouring nettles, and siphons its nourishment through periodic 'plugs' along its stem. The rafflesia has no stem or leaves and only emerges from its host in order to bloom — and it produces the largest single flower: one metre across.

Irena Salina's award-winning documentary investigation into what experts label the most important political and environmental issue of the 21st Century - The World Water Crisis. Salina builds a case against the growing privatization of the world's dwindling fresh water supply with an unflinching focus on politics, pollution, human rights, and the emergence of a domineering world water cartel. Interviews with scientists and activists intelligently reveal the rapidly building crisis, at both the global and human scale, and the film introduces many of the governmental and corporate culprits behind the water grab, while begging the question "CAN ANYONE REALLY OWN WATER?" Beyond identifying the problem, FLOW also gives viewers a look at the people and institutions providing practical solutions to the water crisis and those developing new technologies, which are fast becoming blueprints for a successful global and economic turnaround.

Tony Accardo have taken the reins of the criminal empire built by their mentor Al Capone. Thanks to Sam Giancana's takeover of the policy racket, the gangsters are now making millions. With so much money coming in, Accardo knows they need a place to hide it. They find their answer in a growing city where gambling is now legal: Las Vegas. However, the New York mafia is already there, led by criminal mastermind Meyer Lansky.

Montezuma Dan Snow journeys to the ancient heart of Mexico in search of the lost civilisation of the Aztecs and their last and greatest ruler, Montezuma II (1502-1520). Montezuma inherited an empire of five million people, stretching from present-day Mexico to Nicaragua, from his uncle. His rule was marked by incessant warfare. Enemy states were growing more powerful and conquered tribes were becoming more rebellious. Within months of taking the throne in 1502, he went changed a man of good reason into a pitiless autocrat who declared himself a god, believing that fear and ruthlessness were the only ways to stop the empire falling apart. Yet it was at the hands of Cortes and the Spanish conquistadors that Montezuma met his downfall. But what was his relationship with Cortes, and why did such a ruthless leader submit to his captors with such relative ease? As Dan Snow visits the ruins and picks through current excavations, he pieces together the evidence of a gripping story: a divine tragedy of errors, the clash of civilisations, the end of a world - and a very human God.

Every day our planet faces cataclysmic events that threaten our very existence. Whether from natural or man-made forces, rising from the earth or menacing from space, the world seems beset by more catastrophes than ever. Some believe the signs of the coming Apocalypse are all around us–as outlined in the bible’s most compelling book of prophecies: Revelation". And even the non-religious can’t ignore what appears to be a growing rate of globe-threatening disasters. Are we approaching a biblical “End of Times”? And if so–how will it happen? Will it come from an act of God? Or a colossal misstep of man? Get an uncomfortably close front row seat to some of the most likely apocalyptic scenarios our world faces today–and the history, both scientific and biblical, behind them.

Imagine a world where infinite copies of you are playing out every storyline of your life. It sounds like a plot stolen straight from Hollywood, but far from it. This is the multiverse. Until very recently the whole idea of the multiverse was dismissed as a fantasy, but now this strangest of ideas is at the cutting edge of science. And for a growing number of scientists, the multiverse is the only way we will ever truly make sense of the world we are in. Do multiple universes exist? And if so, which one are we actually in?" Imagine a world where dinosaurs still walk the earth. A world where the Germans won World War II and you are president of the United States. Imagine a world where the laws of physics no longer apply.