Dara and the team shine a light on some of the mysterious and usually hidden worlds surrounding us. Science journalist Alok Jha discovers he is playing host to an entire ecosystem of microbes and amazing new research suggests this is responsible not just for his health but for his mood and mental well-being too. Dr Helen Czerski investigates an amazing new technique developed to combat deadly killer viruses. Professor Mark Miodownik takes a plunge into the miniscule nano-world to see what tricks we can steal from nature as he makes the world's toughest high-performance material. In the studio, it is man versus machine as Dara pits his talents against a computer to identify whether a whisky is fake, whilst Mark reveals some gravity defying liquids.