Written for the Costume Party in Hogwarts (Prompt: Inferi!Regulus).
Cave
Regulus' day didn't start different from any other day.
Cold, dark, and wet.
He had long since lost track of how much time had passed; it was an impossible task without being able to leave the lake—never mind the cave—he was trapped in.
Somehow, he had expected that his afterlife would be different. Dining together in Valhalla, eternal punishment in Tartarus, anything but this. At this point he had almost convinced himself that he would prefer the Cruciatus Curse to this monotony.
As usual, he kept himself near the bottom of the lake. he did not particularly desire to speak with the other Inferi—even if he wondered who they might have been in their lives. Morgana, he didn't even know if he could communicate anymore.
He had never tired. Not once in however-long-he-had-been-here.
There was simply no point in it. He just wanted to suffer alone, was that so much to ask?
Oh, how he wished he had taken anyone with him. Barty, Severus, Sirius, sweet Merlin, even Potter could have helped him. Taking any just one other person with him might have saved his life and prevented him from this.
But he didn't. He didn't because he was fully aware that they would not be able to trust him and vice versa. Not to forget that boat.
Regulus had claimed his usual place at the very bottom of the lake, between two giant stones. It was a rare occasion that he left it, usually when he wanted to give himself the impression he was still somewhat human and pretended that his back had started hurting.
Of course he had long since stopped to feel anything. He was pretty sure that he would still be able to feel extreme pain, but he didn't really have the opportunity to test it.
Something was different today. He did not know what it was, but all the others here seemed to be filled with some wicked form of excitement. There was someone here. Someone they could destroy. And the worst thing was, he could feel the same rising in him. Despite all the effort he spent resisting it, Regulus was becoming one of them. It was simply a matter of time, unavoidable.
When all the other Inferi moved towards the surface, he followed them, carefully keeping a distance of a couple of metres. He almost didn't but the urge was just a bit too strong to ignore.
Then, almost twenty minutes later, It happened. The thing that changed him, that made him just one Inferius of many.
The person that was here had taken water from the lake. From their lake. They could not do that. It was not their lake, it was the lake of the Inferi. Of his Inferi.
He had to protect the lake, the island, and the locket—there was something the matter with the locket. Something important, but the Inferius couldn't remember.
It could not be that important.
It was not that important.
It was irrelevant.
They just needed to make the human one of them.
Please tell me what you think!
~Marvelgeek42