Bill Oddie, cameraman John Aitchison and sound recorder Chris Watson reveal the hidden lives of Britain's animals. Bill sets cameraman John a mission to film elusive bird of prey the Goshawk. To make John's task really tough it has chosen to hang out on the fringes of a military base. Will John succeed with such limited access to his subject? Back on his home turf, Bill is overjoyed to witness the arrival of a wren family into his back garden. But his happiness is short-lived as things take a turn for the worse and suddenly there is a murder mystery to solve. Bill laments the victims and attempts to locate the perpetrator. On a lighter note, Bill turns his musical talents to those of our British song birds. His theory is that by categorising their song into jazz or classical genres it is easier to identify which birds are singing which tune. And if you thought these musings were purely fanciful then there are more surprises as Bill ponders communication with the natural world further - by talking to the trees. He teams up with Chris Watson to listen in to the sounds of a grand old oak. Over the passage of time this ancient old tree has witnessed civil wars, agricultural and industrial revolutions. But in its lifetime generations of the local wildlife have been consistent visitors. Chris places microphones high up in the canopy and deep into the heart of this old tree so that he and Bill can listen in to the hidden sounds that exist within. Away from the countryside and deep within the heart of London, Bill meets Artist Tony Heywood who has always been curious about microscopic life forms and has taken his enthusiasm for the minutiae to new levels with his work Shimmer.