Every year, spectacular seasons transform our planet. As they sweep across the world, they drive all life on earth, bringing huge opportunities and great challenges to everything. This special, narrated by Andrew Scott, celebrates spring on planet Earth, and the extraordinary tricks that animals and plants find to rise to the new challenges it brings. This magical season brings a burst of new life - but as soon as the air starts to warm, it's a race to wake up and get ahead of everyone else. For many, it's the perfect time to find a mate and raise babies - but for everything, from adventurous grizzly bear cubs and amorous dancing grebes, to flowers in the desert and swifts that fly marathons, spring is about rushing to make the most of the opportunities this busy season brings.