The gulper eel is one of the strangest creatures on Earth, and yet it may be more common than you think because it lives in the middle depths of the oceans, which are the biggest of all wildernesses on our planet. Fergus asks John about his ventures into this realm and what it's like to take a submarine down to two miles. You can see this with video images of gulper eel at: https://www.youtube.com/watch?v=7vgryR_Wxrs