In this Earth Report we hitch a ride into the abyss to find a world that we know almost nothing about. Miles below the ocean surface there may be as many as five million species as yet unknown to science. And the way to find them is with an ROV or Remotely Operated Vehicle. ROVs are usually deployed to carry out essential work for the oil industry. Now, through a partnership between the oil industry and a British research centre, they are helping to explore parts of the deep ocean and discover life forms that have never been seen before.