I don't really know if I've read this somewhere of if I just thought about it but here it goes.
Regulus lying in the water ready to accept death soon finds himself swimming back to the surface knowing his brother will think he died serving the dark lord.
Kretchur is gone.. was he under long enough for he to think he died?
That's not what's important, he needs to explain everything to Sirius, Remus, lily,James.... especially James.
As he got out he needed to know where they were. He couldn't go to Dumbledore not again after he asked him for help..
He was so deep in thought he didn't notice he was still wet, and no one around him seemed to notice as he walked in plan sight.
He went to his brother's flat, he could hear screaming and throwing... sounded like sirius heard some bad news, maybe one of his friends died in the war. For marlin sake he hopes that wasn't the case.
Being to frantic he didn't realize he went threw the door instead of opening it, as he entered he can see almost everything is destroyed... he followed the sounds of his brother to find Lupin is now calming sirius down, sirius was sobbing. Yet Regulus couldn't make out what was being said so he slowly approached, Lupin looked up from holding sirius staring in the direction regulus was but didn't say a thing, almost like he didn't see him.
" how could they" , "he was still in school" , " he did everything they asked" he heard threw sobs. He tried asking who he was talking about but found nothing came out but water.. still it didn't get a reaction from the 2 infront of him.
He tried touching them to get their attention, nothing.
He left not able to take the pretending he wasn't there. Even when Lupin clearly saw him walk in... or did he.
He managed to find the potters resistance, it was actually easy to find considering he was under the impression he needed a secret code to get to them.
As he arrives he could hear James crying. He rushed in to see a red face James being held by a clearly pregnant lily.
Kneeling infront of James holding his hand, he looked at lily for answers to who died, still nothing.
"Reggie... how... why..." were the only words Potter was able to say between sobs.
Was it him he was talking to or was he talking about him. His cold wet hands still holding on the the hands of the sobbing James.
Then he heard lily speak. " they could still find him, I know Reggie has been gone awhile b..." she was cut off as James stood. Regulus had fallen back by surprise. They couldn't see him could they?
"He's dead and you know it, they probably found out, they probably killed him themselves and covered it up" James horse voice spoke.
Regulus stood up, he was right there and they were talking about him , Regulus Black, as if he were dead. How could that be he was right there. " Jamie..." he finally got out " I'm right here, can't you see me."
James continued to grow mad as he was still crying trying to accept the death of his best friends brother, his first love, his soul mate. Regulus tried everything he could to show himself.
The more he tried the more he realized he was like a ghost, no he is a ghost stuck at 17, he died in that cave, lily is pregnant probably about the burst any moment, she wasn't a few weeks ago.
Regulus started looking for the date, anything to know how long he was gone. He left the room the 2 were grieving to find out how long he was there.
That's not right its supposed to be 1979 and it was definitely not may, was it?
He started spiraling, he went to everyone he knew to find someone who can see him. Even if that ment confronting dumbledore.
Dumbledore being his last option he went to hogwarts, school seemed empty, of course it was he was there at midnight. Looking everywhere he finally went to Dumbledore office.
There stood Dumbledore at his desk. He looks at the young black brother. Or at least in his direction regulus thought no one else has been able to see me so why could he.
" I see the rumor is true."
Was he talking to himself?
Regulus walked closer and slowly zigzagged to see if it was him the headmaster was watching.
It was, he could see him, but how?
" it seems Mr black you have died. A very wet death may I say" he said in a calm voice
How could he be so calm? A dead student is right infront of him. A dead student who begged him for help , who shouldn't even be here despite how desperate he was to be seen, to be heard.
"You..." Regulus started " you can see me?"
"Of course, it's not impossible to see the dead"
Regulus hated this, the only person who could see him was the one who wouldn't help. Even though he new this he still tried.
"Please protect them, James, sirius.."
Dumbledore moved around his desk " there's nothing I can do if something were to happen, the Potters are under a protection spell already"
" Move them, tell them Pettigrew..." he was cut off
" any information you give me won't be useful, it has no evidence, no reliable sources "
" I'm right here telling you!!, check his arm he has the mark!"
" so do you I'm afraid you can't be trusted my dear boy"
" I was a spy and you know that"
Dumbledore looks at his peninsula then back at the boy " for which side tho, you weren't necessarily fully helpful"
Regulus couldn't take it , he tried throwing things, hitting the man but yet again nothing happened. Dumbledore went over to the peninsula to remove the memory of their conversations right infront of him.
He tried to stop it but he seemed to have no effect on the world.
For awhile he kept trying to get threw to someone. But after awhile he kinda just watched. He watched his best friend pandora have a beautiful baby girl and Jamie have a boy who was the spinning image of him but of course with lily's eyes.
He'd notice for a little the young ones saw him so he'd play with them, he watched over them.
Then it happened, Pandora died, then the potters died. He couldn't do anything, he tried and felt to helpless.
He watched his brother get wrongfully accused, he watched as Pettigrew ran off. He watched as snape came and cry holding lily. He watched them take Harry away. What else could he do?
He noticed lily and James crossed over quickly, he didn't even get to see them.
That's when he realized, why was he stuck there? Why couldn't he cross over with the rest?
He went back to the cave to try and cross over. He layed in the water.
Ever so often he'd try again, he was bound to the water.
Then he thought he saw James and tried grabbing him. Asking him to help.
Why didn't he recognize him? Why wouldn't he help?
It was harry all grown up. And he, regulus black, had almost took him down with him.
So regulus accepted his fate to stay there forever in that cave to be alone because all he can do now is cause harm and pain to others and why would dumbledore ever help him after he let him die, let James Potter die, let Lily Evans die even with his warning.