David begins his journey inside the magnificent Palm House, a unique global rain forest in London. He explores the extraordinary plants that are so well adapted to wet and humid environments and unravels the intimate relationships between wet zone plants and the animals that depend on them.

David begins with the secret world of plant movement and uses sinister carnivorous plants to show just how active plants can be. As the seasons change, David demonstrates how plants operate on a different time scale to us; how they modify their lives according to the time of year.

David discovers the plants that have evolved to shed their dependency on water enabling them to survive in the driest environments.