Ant colonies are one of the wonders of nature - complex, organised and mysterious. This programme reveals the secret, underground world of the ant colony in a way that's never been seen before. At its heart is a massive, full-scale ant nest, specially designed and built to allow cameras to see its inner workings. The nest is a new home for a million-strong colony of leafcutter ants from Trinidad. For a month, entomologist Dr George McGavin and leafcutter expert Professor Adam Hart capture every aspect of the life of the colony, using time-lapse cameras, microscopes, microphones and radio tracking technology.

Adam Rutherford meets a new creature created by American scientists, the spider-goat. It is part goat, part spider, and its milk can be used to create artificial spider's web. It is part of a new field of research, synthetic biology, with a radical aim: to break down nature into spare parts so that we can rebuild it however we please. This technology is already being used to make bio-diesel to power cars. Other researchers are looking at how we might, one day, control human emotions by sending 'biological machines' into our brains.

Nathan stages a ninth birthday party for Adam, but faces a problem when Remy, one of the child actors who played Adam at age six, becomes attached to Nathan, calling him 'daddy' even after his scenes are over. Remy's mother explains that her son might have trouble understanding the difference between acting and reality. To discover what went wrong, Nathan repeats Remy's scenes with different actors including Liam (a nine-year-old Adam actor), an adult actor, and a mannequin. He then explores what might have happened if Angela had stayed with him and meets with the real Angela, who urges him to forgive himself, as her religious beliefs state.
In an attempt to truly understand the connection between parent and child, Nathan stages a new scenario in which he is Remy's mother Amber and Liam portrays Remy. They re-create the experience of appearing on The Rehearsal and becoming attached to 'pretend daddy' Nathan. After coming to the emotional realization that they should not have done the show, Nathan as Amber seemingly breaks character and tells the fake Remy, 'I'm your daddy.'

Dr Adam Rutherford takes the viewer on a rollercoaster ride as he explores the consequences of one of the biggest scientific projects of all time - the decoding of the entire human genome in 2000. In The Book of Life Adam discovers that every human carries the entire story of life on earth hidden in his or her DNA and sees how we are all linked directly to the origins of life and to the first creatures with backbones. He also investigates the implications of the fact that for much of its existence, the human race was an endangered species.

Dr Adam Rutherford tells the extraordinary story of the scientific quest to discover the secrets of the cell and of life itself. Every living thing is made of cells, microscopic building blocks of almost unimaginable power and complexity. The first part explores how centuries of scientific and religious dogma were overturned by the earliest discoveries of the existence of cells, and how scientists came to realize that there was, literally, more to life than meets the eye.

To recruit actors for his rehearsals, Nathan opens an acting studio in Los Angeles, teaching 'the Fielder Method', which involves covertly observing and imitating unaware subjects. Feeling insecure about his own performance, Nathan reenacts the class with actors and a fake Nathan as the teacher while the real Nathan plays the role of Thomas, a student. Nathan makes his students immerse themselves in other people's lives while he immerses himself in Thomas's life, even living in Thomas's home.
Nathan returns to Oregon, where his 'son', Adam, is now a teenager. Nathan and Joshua, the actor playing Adam, decide that Adam should lash out due to resentment of his absentee father and develop a drug problem, a situation that mirrors Angela's own past. Adam suffers an overdose and is tended to by emergency responders played by Thomas and another Fielder Method graduate. After he runs away from home, the 15-year-old Adam reverts to a 6-year-old since Nathan plans to relive his son's earlier years.