Earth a 4.5 billion year old planet which is still very much evolving and as continents shift and clash due to tectonic plate movement volcanos erupt and glaciers grow and recede, the Earths crust is carved in numerous and fascinating ways, leaving a trail of geological mysteries behind.

In this film we explore the Mariana Trench, it is the deepest place on Earth, its sheer walls cut 7 miles into the Pacific ocean and the mystery of what created this deep dark chasm takes scientific detectives on some of the most dangerous dives ever attempted deep into the abyss.

Scouring the oceans floor scientists uncover a strange undersea world of fiery mountains, bizarre mud volcanos and the largest geologic structure on Earth. Discoveries from this deep underwater world will revolutionise our understanding of the powerful forces which shape not just the trench but the Earth itself.