At the bottom of the vertical shafts, Krem Um Ladaw changes character and breaks into a horizontal river passage containing moderately sized pools of water where dozens and dozens of fish have evolved to live in complete darkness. Finding the fish is one thing, catching them is another matter altogether. When marine biologist Dan Harries (centre) first discovered the fish during the February 2019 expedition, he was amazed and perplexed. “My first reaction upon seeing the fish myself was, I’m going to need a bigger net.” And a bigger net he got.