Delving beneath the surface area in the Earth’s oceans to uncover a world of amazing extremes, like crushing depths, stormy coasts, broad blue deserts, and crowded reefs; how seals fend off sharks; how orcas fight to survive.The highest mountains on this planet are residence to snow leopards, golden eagles, mountain goats, barnacle goslings, and

The story plus the setting was good enough for it being stand alone episode. Although I did benefit from the subtle scene references from the primary Sherlock. Extra importantly the episode for god sake just required have a very good solid ending. I'm positive a lot of the viewers would complain about how the makers tried much too tough to pull off