Britain's road network might seem like an unlikely starting point to look for wild things but in the last 50 years the roadsides have become our latest nature reserve. Chris, Lottie, Trevor and Sally explore Birmingham's hard shoulders and soft verges, and discover how Danish scurvy-grass has become the fastest moving plant in Britain, using a fast car, a slow-motion camera and polystyrene balls. They also reveal how a very familiar British flower has come under threat from a roadside imposter, and they find the world's smallest 'bear' living in the last place imaginable.
The team visit Salisbury Plain to investigate why a military no-go zone provides the perfect conditions for wild things to grow. Using explosive stunts and underground experiments, they explore how wild plants have developed their own defence systems to survive, with battleground manoeuvres creating perfect conditions in the soil. Exploding a poppy reveals the secret to the long life of their seeds, and going deep into a puddle uncovers a microscopic battleground, with each tiny wild thing trying to make the most of the temporary conditions. And Britain's most explosive plant takes on a British Army assault rifle, demonstrating that it has an even faster ballistic system.
The team visit Chris's home patch to discover how changes over the past 50 years have made the Yorkshire Dales habitat to many a rare wild thing. Chris explores the ancient wildflower meadows through the eyes of a bee. Dr Trevor Dines turns security guard as he helps protect Britain's rarest wild plant - the lady's slipper orchid. Sally Eaton discovers how music helps bees to make honey.
Chris and the team visit Merseyside. Industry, trade and goods have come and gone, and so have the wild things. Dr Trevor Dines dons his wetsuit to discover how an invasive pond plant, New Zealand pygmyweed, has found a way to grow in the dark. Chris uses a frying pan to test the sticking power of a tiny barnacle, and Sally hunts for the dead bodies of lichen in a Tudor manor house loft, to find out how our environment has changed over the past 500 years.