Just in case the thing didn’t post about the shadow thing on subnautica, I’ll just repost it.

The shadow thing is normal, and is part of the story. It’ll appear again in the active lava zone (around 1400 meters.) so don’t worry about it, just part of the story of something you’ll meet in the alien base at the active lava zone. Also, find the entrance to the lava castle at the inactive lava zone (around 1200 meters.) and if your confused about the lava castle when you get there, it’s in the middle of the inactive lava zone, the huge rock formation. Find the entrance, explore it (maybe grab some kyanite while your there too) until you find the alien base hidden in that place. Don’t worry about bringing ion cubes, there is already a ion cube fabricator there (requires drill arm for PRAWN.) but scan the blue ion tablet and make another one of those. After that, find the portal which leads to the alien gun. And I forgot to mention, once you get depth module MK II for PRAWN, bring a purple ion table. You need it in the lava castle alien base to learn ion batteries and ion power cells. (required for rocket to complete game.) This should be everything you need to know at this point, so use it wisely. Oh yeah, make sure you have a grapple arm for your PRAWN suit to go fast.

-Lamprey