Documentary following the impact of the seasons on the diverse array of wildlife living in Loch Lomond and the Trossachs National Park. The first edition sees the arrival of spring after a merciless winter, with the melting snow forcing the mountain hares to keep their heads down to avoid becoming a meal for a golden eagle, while pregnant red deer head down to the glens to calve. The park's ospreys return from west Africa to breed, two male black grouse fight for the right to mate, and an eagle chick waits patiently for its parents to return with food.