Alex had told Artyom, when he was young, that when the bombs fell, Alex had felt a wave of burning all over his body for the briefest instant, and then nothingness; "It hurt a little in my heart, for a while," he said, softly, "but not forever, Artyom." It would be no surprise if Artyom never felt an alien pain; nothing was wrong with him if he didn't; it was just the world they lived in now, a world where only the handful of Moskvich who'd made it to the tunnels were left.
But Artyom had felt things.
He'd felt-- oh, so many things, sore muscles and bruises and cuts and deep pangs of hunger even when he'd eaten, the occasional truly strange pain, sometimes what felt like monster claws on his chest or teeth on his arms-- whoever his soulmate was, she led an exciting life. He thought about it often, wrote about it in his journals, wondered what she'd done to get the cut on her face, or where she was that was so cold his skin prickled all day as he worked in the mushroom farm. He also wondered if she wondered about him-- wondered when he was thirteen and his legs ached every night with his growth, wondered what had happened when he had his first cigarette and had vomited awful throat-burning bile all over Eugene's pants, wondered when he played guitar too long and his fingers had started blistering. He wondered if he would ever meet her. He wondered if she was a Red or a Nazi (he hopes not), or Hanza, or from distant shining Polis...
Unlike so many other people living in the apocalypse, his pain had never faded after a sudden awful burst, and it was a strange comfort, some nights, feeling aches not his own, knowing that somewhere out there, under the same barren city, there was someone who was hurting his hurts as well...
He'd wondered and speculated and daydreamed for so long that it took him much too long to realize what was happening.
Of course his throat and lungs burned when they were on that haunted plane, the irradiated air of Moscow singeing down his throat; of course he'd felt a panicky lack of breath when he'd seen Pavel dangling and struggling from the noose; why wouldn't Pavel wince and stumble in pain when they were fleeing the Nazis and a bullet thudding against Artyom's armor, knocking him breathless to the floor? It was all dangerous, they were both often hurt-- and if Pavel had looked pale and shaking as he took orders from Korbut, Artyom hanging there in a tortured daze, Artyom could hardly be blamed for missing it. He wasn't looking for it. He didn't know.
That's what he told himself, when the baby Dark One told him, There's someone up ahead-- oh, strange! His heart is connected with yours, Artyom.
Artyom stilled in the shadow of a building, and the Dark One continued, There are others with him. I think they mean to hurt you. I'll help.
There was no time to think about it, no time to ask the Dark One what he meant, and anyways-- Artyom knew what he meant. Of course he knew what it meant. But now-- now was too late to wonder if Pavel knew, too; Artyom had to move forward, connected hearts or not, even as panic choked his throat.
It's too late. It's too late, it's too late, he told himself, over and over, as he killed Pavel's comrades, as he chased the man up the stairs, following his taunts, as he felt the burning soulmate-pain of a bullet buried in his side, and then it was the two of them, alone--
"Davai, davai," Pavel was urging him, coughing and slumped, his blue eyes dulled by his gasmask, and Artyom swallowed, knelt beside the man; it would be easy to slice his throat. It wouldn't be the first or fiftieth throat Artyom has cut open. "Come on, finish the job," his soulmate told him.
Instead, Artyom turned the knife over, and slashed his own hand open, watched Pavel wince and cry out at the sudden pain--
But it's too late, he told himself again, and called the Dark One up, to lead him into Pavel's memories. Too late, he thought, when he shoved a new filter onto Pavel's mask, and the Dark One wondered if it was mercy or selfishness, that Artyom spared the man whose heart he shared. Too late, he cried inside, as he fled the building and the square and the revelation, leaving them far behind, hoping and dreading that Pavel would survive.
Weeks later, Artyom woke up to the pain of monstrous teeth digging into his arms, and he he didn't know why he cried.