This episode takes us to the most beguiling parts of the sea, the very depths that we know so little about. We join a team of scientists, ranging from biologists to vulcanologists, on an international expedition as they return to the Mariana Arc, on the Pacific Rim of Fire.

Original broadcast on television as part of the series The nature of things. Teaching guide available under Additional Info tag. Also available as streaming on Curio.

Chaptered: The Pacific ring of fire Bioluminescence Deep sea resources Beyond the terrestrial view.