We're going to go on a dive to the deep sea, and anyone that's had that lovely opportunity knows that for about two and half hours on the way down, it's a perfectly positively pitch-black world.
Vi skal foreta et dykk på de dype hav, og de som har hatt muligheten vet at i omtrent to og en halv time på veien ned vil det være fullstendig bekmørkt.