THE SLAVE TRAIL. The world still keeps many secrets, some just waiting to be revealed, if you just listen, led by a sound hunter. A peaceful and nomadic hunter, who unveils a hidden aspect of the Unesco World Heritage sites, their soundscape. Equipped with a battery of microphones and a laptop, Christian Holl travels around the world recording cries, rustlings and echoes. With this material, he creates melodies that send us back in immemorial times. Step by step, he gives birth to music : hymns of lands, of men, of animals and plants.