In the hidden kingdom of Mustang, a crack restoration team tries to prevent priceless medieval Buddhist murals from crumbling into dust.

Mustang is a tiny kingdom barely touched by time, hemmed in by the world's tallest peaks along the northern border of Nepal. This speck of neglected land conceals a spectacular treasure from the past - the monastery of Thubchen, decorated with astonishing intricate and expressive medieval wall paintings. Severely damaged by a leaking roof and stained by soot from the butter lamps of devout monks, the paintings are crumbling fast. Can a crack team of architects and art conservators save these unique survivals of Tibetan Buddhist art? Many local people want the images to be completely repainted, an act that they believe will restore their spiritual power. This clash between the values of western conservation and the beliefs that inspired the paintings adds to the drama of this program, shot inside a Shangri-La kingdom that has kept its secrets for centuries.