When you’ve done all you can (or care to) do, return to the Research Base and talk to the Third Fleet Captain to try descending into the Rotten Vale again. With Legiana gone, there should be no further serious threats from the skies. After some babble from the Third Fleet Captain the quest Into the Bowels of the Vale will begin.

You’ll shortly find yourself in the depth of the Rotten Vale, in AREA 11, adjoining AREA 9 and AREA 8, beyond the toxic mist. While it was once blocked off, you can now access the upper portions of the Rotten Vale on foot, so long as you’re willing to suffer from the toxin. Alternatively, you can find a shortcut cave in AREA 10 which will take you back up to AREA 2 without any fuss. Convenient.

Jump down some ledges and head downhill to the southeast and into AREA 12, where you’ll find a cavern filled with what seems like fresh water. As with everything in the Rotten Vale, though, you should expect the worst of it, a point this caustic fluid will reinforce. Be on the lookout for signs of Zorah Magdaros’s passage as you go until you ultimately reach AREA 14, where another magmatic stone pustule can be found. After some chatter between your hunter and The Handler, a new monster - Odogaron - will show up… and it doesn’t want to be your friend. Fortunately the same huntress who saved you in the Coral Highlands shows up and distracts the monster.