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.