Dysphoria

He remembers the first time he began to experience the dreams. It was not long after he had built his base in the Grand Reef near a piece of the Aurora, a good point to access the deeper parts of that region and even get to the Lost River, but at that point he did not know this.

The shelter had quickly been completed, food and water secured thanks to filtration machines and grow beds. Creating his room had also been nice, the view of the Anchor Pods and Membrane Trees is soothing whenever he looked out his window into the dark ocean beyond.

An unintentional comfort during the most trying of times.

His bed is, without a doubt, the best part of his newest habitation. A bit stiff for his own tastes but it is much better than sleeping on the cold, hard floor all the time.

And then the dreams started happening.

The dreams always begin the same. He is floating on waves, in the ocean of Planet 4546B. He does not know how he got there or why, but he fills up his oxygen tanks while he still can.

Then he swims down.

Legs kick back and forth, arms paddle through the water, and bubbles escape his mask as he pushes himself deeper and deeper into the inky abyss below him.

There is never any land around him. No underwater islands, no rocky landforms that shoot up out of the darkness, nothing for him to use to keep track of how far down he is. There is only him and the slowly fading light.

The ocean is silent.

And he keeps swimming.

His goal is never clear, all he knows is that he has to keep swimming down, an instinctive urge not for his survival, but for something else. It is like there is a chord attached to his chest, constantly tugging him down.

An excited child pulling at their parent's arm in an attempt to show them something interesting.

Just as the darkness of the ocean starts closing in he wakes up. He is always confused, expecting himself to still be swimming when he sits up in his bed, but he ultimately disregards the dreams as a side effect of how much time he spent in the alien ocean.

After encountering the Sea Emperor Leviathan he assumed that the dreams had happened because of her. That they were her way of calling him down to the Primary Containment Facility so he could help her hatch the eggs that would be his salvation.

So he stayed with her until her final moments, watching her breathing slow to a stop and praying that the dreams would to.

They continued.

He swims deeper, the tugging sensation within his chest growing stronger.

Now he manages to pierce through the darkness that makes up the lower part of the ocean in his mind. He sees nothing, but he can feel... things swimming with him.

Large creatures, the size of the Ghost Leviathan he had encountered on the edge of the crater when he had stupidly decided to explore so far away from his base. Though he is certain the monstrous beings are not a species he has ever encountered before

However none of them notice him, and he keeps swimming.

There are several times in his dreams where he runs out of air, the precious oxygen in his tanks hitting zero, but he wakes up before he suffocates, gasping for breath. It was like he had truly been drowning.

Then again, just like Marguerit said, he had always been drowning on that planet, just very slowly.

Now back on his home planet, in his bedroom and not the ocean he had been subjected to for a month and a half he expects the dreams to end.