"Valar morghulis" the voice whispered into his head, as it had done so often after he had become the master of death. The voice was never the same but these words were. They were important, he just couldn't figure out how… it was no spell and it didn't seem to be in any language which was still alive, "Valar morghulis"
There it was again, distracting him from grading homework. That's right, Harry was a teacher. Defense against the dark arts of course!
He might've once wanted to be an auror but he had seen enough dark lords for one lifetime. Instead, he taught the next generation, so that they might one day rise up to face any new dark lord as he and his friends had done against Voldemort.
"Valar morghulis"
"Persistent, aren't you?" Harry asked the voice dryly. He had never tried talking to it before. Why would he? It was just a voice in his head but it seemed as though that had actually done something. There was a buzzing, like a pesky fly directly in his ear, loud, all consuming. His vision blurred and -for the first time in ten years- his scar hurt, like someone pressed a branding iron onto it and then… everything went dark.
When he opened his eyes again, he was no longer in Hogwarts castle. He was in a plain, warm sunlight bathed the endless sea of grass.
He flashed back to his fourth year, the graveyard, the portkey. Panicked, he tried appariting back to his home but nothing happened. That was… strange. How far had this voice taken him? Apparition should've at least taken him a few kilometres, even if the target destination was too far away…
Something like this only happened either under anti apparition charms or when you were very, very far away from your destination.
"Okay, let's think on this. Hot weather, plains… Africa maybe? Kreacher ?" He called out for the grumpy house elf. Nothing. Now that, that scared him. A house elf could reach their master anywhere in the world. Was he… no longer on earth?
"Valar Morghulis", there was the voice again.
A thousand questions stirred in his mind but one crystallised, "What are you?"
Something powerful enough to pull him from his plain of existence and drop him here? He didn't even know where 'here' was. He could see no river, no cities, no-
The thunder rolled in without lightning… no it wasn't thunder, it was the sound of thousands of horses riding in unison. His eyes snapped to the noise. A front of horses with dark skinned riders, rushing in like a typhoon. They were carrying swords and bows. Bows with arrows, arrows which they fired at him.
In a split second, the elder wand appeared in his hand, "Protego!"
Around a dozen arrows hit his barrier. Had he been a second later, he would've been impaled. His battle instincts kicked in. Expelliarmus? Useless against such a horde… they were clearly tribal… maybe a big show of magic could scare them off? Harry remembered a spell that Voldemort had once used. He didn't need to say the spell as he breathed out fire, twisting into the form of a flaming serpent, as big as the basilisk in the chamber of secrets.
The attacker's horses protested. The riders spoke in a rough and alien language. When they didn't leave, he decided to let the serpent chase after them. He had expected them to run but no, they rode right into the fire, as if expecting to slay the mighty beast. Of course, being made of pure fire, it couldn't be hurt by their swords or arrows. When half of them had died, their leader barked orders and they retreated. They were intelligent enough to recognise when they had no chance, though not as intelligent as to run when they saw his spell at first. The end of their lives left a bitter taste in his mouth.
He wasn't as idealistic as he had once been but he certainly wasn't some psychopath, killing for pleasure like Voldemort did. As master of death, he could feel when they died, like droplets of water falling into an ocean, small ripples, barely noticeable but still there.
He had gotten used to that but what was new were the threads which blossomed in his gut. Not physical threads but spiritual ones, similar to the one which had appeared when he became an animagus, just like with his animal form, he could tug at the strings and change. It didn't feel like the animagus transformation but more like polyjuice potion. Flesh, bone and hair shifted. Looking down at his hands, they were the same shade as the riders who had died. With a quick flick of his wand, he conjured a mirror and sure enough, he looked like the rider, clothes and all.
Master of death… was this what it meant? But why hadn't it happened before? Had it something to do with these strange lands?
He transformed back and pondered… how to find a city? Looks like he would have to take a different perspective up top. He tugged at the string of his animagus form. He shifted, smaller, more compact, an owl. He rose higher and higher, how he loved flying but he couldn't enjoy it right now. First he looked in every direction north, west, south- bingo, a city. A few days away by foot, maybe one and a half by flight. There was a small river which he could follow for a day or two, due south west, until he needed to go due south. He landed and transformed back. Why didn't he fly there? He had no idea if owls were even a thing here, if they weren't, one flying here would garner too many strange looks and if someone saw him transform, he might lose an edge which he could desperately need. The riders were easy enough to deal with but what if there were other wizards here? He should keep a low profile for now.