Author's Note: While writing this, I'd been looking at the same chapters where all this happened so just be aware that I've more than already mis-timed and mis-wrote certain both big and small events. I'm not putting any effort into this, so it's not great.
Sometimes Time is All One Needs
After Harry recovered from the vision of Voldemort torturing Sirius, after reporting and receiving no aid, after Kreacher's less than helpful information, he was blessed with a moment to think, he just knew something horrible would happen no matter what he'd do, and this feeling sat uncomfortably in his stomach. "Harry? What should we do? Harry?" came the voice of his female best friend, Hermione Granger. It was full of concern for him and Sirius. The concern just wrought more pressure upon him, more than he felt he could handle yet he would not show it. In the small clearing of trees where Harry, Ron, Hermione, Ginny, Neville, and Luna stood, a thestral came up to Harry, noticing Grawp's blood, caused by the centaurs who shot arrows at the giant's face, on his sleeve.
"I guess we could try thestrals..." Harry pondered, he was rather forcefully convinced into letting the rest of them to aid him in rescuing Sirius from Voldemort and they were unable, until that point, to decide on how to get to the ministry in time. Though with all of them accompanying him along, the feeling in his stomach felt as though it would explode and consume him.
"Thestrals? Those horse things that you can only see if you've seen someone snuff it?" Ron asked, shuddering slightly. Harry only nodded.
"The only problem though, is how we're going to get all of us to the ministry, how will we be able to attract enough here?" Harry then asked.
"In case you haven't noticed, "Luna said to him, looking slightly incredulously at him, "You and Hermione are covered in blood, it should be easy to get 3 or 4 other thestrals to come here."
And so, despite feeling as though he would collapse, Harry aided his friends onto the night black flying horses, with some discomfort by those who were unable to see, and they were off. At the ministry, Harry felt rather impatient and said loudly to the automated visitor's entrance, "FINE! Now can we move?" after being told the customary procedure for normal visits.
They went down to the Department of Mysteries and after a slight dizzying and blinding experience due to the spinning walls and doors, they found a room full of strange creatures, most notably one with weird aquatic brains. After returning to the hall of doors, Harry found an empty amphitheater with an archway at the bottom. This archway had a veil fluttering about as though there was a very light breeze passing by despite being indoors. Harry swore he heard a voice speaking to him but his friends managed to pull him away. So far all of this was very disconcerting to Harry and only helped along the feeling that things were about to go very wrong.
His intuition proved right and they were soon surrounded after they had found the location of the prophecy that seemed to be connected to him but they managed to escape. Harry was separated from all but Hermione and they ended up back in a room they had passed through earlier, a room of time. They managed to get one death eater to crash into one of the many artifacts and his head was transforming to a baby's and back. He didn't know why he did it but as Dolohov appeared, Harry cursed him out of the way and began rummaging through the desks and cabinets that lined the opposite side of the baby-headed death eater and soon found what he was looking for, despite Hermione's insistence that they leave immediately.
The battle escalated to the point that all of them ended up regrouping in the Veil Room, fighting at a major disadvantage. Then the Order arrived along with Sirius which confirmed the fact that Harry already knew, that this was all a trap set by Voldemort. It got so intense that he fought against Bellatrix Lestrange, the crazed witch.
The feeling in his body that Harry had been feeling before all of this had started seemed to shake violently, telling Harry to be careful. Bellatrix, to the surprise of all who was seeing her duel Harry, cast a simple stunner but Sirius got in the way and deflected it and then Harry, held back by one of the Order, watched as Sirius dueled and was felled by another simple stunner. Seeing the look on Sirius' face before he fell through the Veil, which was surprisingly serene, made Harry calm, so strangely calm even he was scared of himself.
He grabbed the time turner that he'd put in his pocket and placed it around his neck. Shoving Lupin out of the way, Harry screamed at the Veil as though Sirius would come back but when no sound indicating his godfather's return came back, he knew but did not yet act. He began to send curse after hex after jinx after curse at Bellatrix who laughed maniacally and deflected all the spells he'd sent somewhere to the side. He got angry again, the calm of shock at Sirius' death melting away and he charged at her, intending to tackle Bellatrix to the ground and pummel the life out of her. She grabbed a long dagger from somewhere within her robes and let out a bark of insanity.
Harry was knocked down by someone as Bellatrix would've been able to stab the life out of him and that someone took the blade into the chest. That someone turned out to be Ron who'd saw Harry running after the crazed witch and after managing to disable his enemies, he charged, intending to save Harry from the blade which he could not see. That blade slid deeper and deeper until Bellatrix buried it to the hilt, twisted the blade, and pulled it out, effectively killing Ron.
This was it. This was the feeling he'd been feeling. Harry knew he had to act now.
He turned the turner three times and found his world disappearing away in a blur, the battle and the sounds shutting out quite suddenly. He then appeared quite alone in the amphitheater looking around. "I... it worked..." He looked at his watch and saw that him and his group would be coming soon. He made his way to the suddenly quiet Hall of Prophecies and found the orb safe and sound. He put it into his robes and headed to the visitor's entrance to wait, as no one was there to disturb him. Looking at his watch about one and a half hours later, he knew he had to move. He placed the prophecy at the floor of the visitor's entrance, along with a small scrap of parchment telling his past self to take it and return to Hogwarts, that it was a trap, and that Sirius was safe.
Hoping it would work, Harry made his way back to the Hall of Prophecies, waiting and watching. When the time passed for his arrival, he knew he and his friends were safe. However, the death eaters who'd been lying in wait appeared in anger at the missing prophecy earlier and Harry aimed and cast twelve high-powered cutting charms at their necks. Not expecting an ambush themselves, they were all quickly taken down, their blood seeping out and covering the floor of the hall. Harry returned to the time room, now quiet, and placed the time turner atop one of the cabinets.
Although now quite fearful, Harry felt that no one should learn that he had come from the future and headed to the room of the veil and stepped in front. The voices this time didn't sound quite so weird, but rather inviting.
'Strange this, time, I wonder if, when I die, I'll simply evaporate or I'll merge when the past me dies, hopefully in the far future.' With a smile that his past self and friends were safe, he stepped through the arch.