It wasn't really in Remus' nature to panic. Logic was sort of his instinctive reaction rather than the whole 'fight or flight' thing. But that all sort of flew out the window when he heard a voice that was so, so familiar. A voice he hadn't heard in a long time, especially that wasn't laced with the edge of war or shouting at him angrily, whipping him with a verbal onslaught of feelings construed in a vicious, angry argument. Sirius, he thought. And in that moment, Remus was terrified.
Terrified, because he knew if he turned around he'd either be faced with a cruel hallucination of his best friend, or worse, he'd see Sirius actually there. But he couldn't be, right? Sirius was in prison, locked away for a crime Remus truly in his heart of hearts did not believe he ever could do, but after being told otherwise -- once to the point of being threatened to be put in prison as well as an accomplice -- he'd just stopped arguing.
So many times over the course of the past several months, Remus had thought about what it would be like to see Sirius again, but it was a very painful thought and one he tried to bury whenever it surfaced. In those rare moments he did think it through, he still didn't know what he'd do or what he'd say. Sometimes he thought he might scream at him, demand to know what happened and not let up until Sirius confessed. Other times he thought he might sink to the ground of Azkaban and fall completely apart weeping, unable to even speak.
Now it appeared he was faced with that very scenario, only they weren't at Azkaban prison. They were in some place unknown. That is, if it really was Sirius. Remus cleared his throat. "I've... I've only just arrived," he said, forcing his tone to be smooth and even as he slowly turned around in the direction the voice came from. The sight of him -- for Merlin's sake -- he looked like Sirius. Before the war, before the loss, before all their arguments that ended in tears and anger. This had to be some cruel spell put on him.
"Only I'm not certain where I've arrived to," he added once he was able to formulate words again.