Forests are far more complex than previously imagined. The documentary, filmed in 4K, travels deep into the remote forests of the Kalkalpen National Park in Austria - the largest area of wilderness in the Alps. Abandoned and unmanaged by man for close to a quarter of a century, the forest's dramatic cycle of growth and decay now rules the landscape. What appears at first to be devastation and destruction is in fact part of the fundamental process of the forest's regeneration and transformation back to its natural, primeval state.