In the fifth episode of the series, lavish imperial games at the Colosseum are highlighted by the emperor's bloody victories, but his paranoid abuses of power lead to a final betrayal.

In the last episode of the series, lavish imperial games at the Colosseum are highlighted by the emperor's bloody victories, but his paranoid abuses of power lead to a final betrayal.

Lurking in the shadows of the Internet, a faceless modern-day bogeyman has attracted the attention and fear of a young generation who whisper his name online. Slenderman lives on the dark pages of the web, where impressionable youth create and cultivate his mythos in message boards, YouTube clips and various other digital incantations. But the online fairy tale becomes a shocking real-life horror as two 12-year-old girls, guided by their devotion to Slenderman, lure their friend into the woods to attempt a seemingly inexplicable, brutal murder. From the depths of one the Internet's most unsettling creations to the court case that must consider the consequences, Beware the Slenderman brings to light questions of accountability in an age where young, growing minds are only a few clicks away from creating and consuming something that may influence them to commit unspeakable crimes.

Could we get all our energy needs from sea water and the salt it contains? Are we to witness a time when salt will power our engines and factories, and light up our cities? Could this be the final curtain not only for shale gas and oil, but also the burning of fossil fuels and the beginning of a gentler form of energy that is definitely renewable? This documentary explores the latest research on sea water and the way scientists all over the world are working on 'Blue Energy'. This research could bring about a major change in our time.

Why were the most fearsome warriors our planet has ever known stopped by a flaming light in the sky? How did Columbus use secret knowledge of the heavens to cheat death in the New World? Our ancestors saw a universe filled with bad omens. The film examines the interpretations by ancient peoples of celestial phenomena as bad omens, and the impact that the perceived omens may have had on history.

Take another walk on the wild side with our favourite pets. Extraordinary photography reveals their hidden senses and secret communication skills. Dogs take a car trip through Paris, using their legendary sense of smell to show us a very different city. A hamster uses his remarkable senses to stage a great escape and then deploys more navigational talents to find his way home. Cats become intoxicated on the scent of a plant and suffer the consequences. A budgie shows his hidden charms to his mate as, under UV light, his crown and cheeks positively glow. Goldfish reveal secret senses that can detect the slightest water movement. A guinea pig gives birth and the newborns receive surprising care from their father. In South America, where guinea pigs have lived with people for 7,000 years, they express the true meaning of their entertaining calls. When we groom a horse we speak their language, but horses use ears to communicate in ways that we are rarely aware of. In Japan cats show their secret messages and in Peru dogs reveal the hidden signs that allow them to communicate across a city. Packed with extraordinary facts and wild behaviour - you'll never look at your pet in the same way again