The place Tina brought Credence was similar to the one where he'd stayed when MACUSA had first picked him up, but it was subtly different. The walls here were white, instead of dark gray, and though the place fairly vibrated with magic, it wasn't the sort that tended to set his teeth on edge. Still, he couldn't help but feel unease coil in his stomach. It was so quiet. So barren.

They strode down a lengthy corridor that was lit every few feet by a glaringly white globe of light that hovered near the ceiling. In front of him, Tina walked with enough purpose that her singed leather coat flapped behind her and trailed strange shadows on the hard stone floor. He matched her stride easily enough, but it was difficult not to give her wide berth when she clutched her wand like a knife in one balled-up fist. They passed like a storm, Credence thought, with something like thunder in his heart and something like lightning in Tina's eyes. May the Lord have mercy on whomever crossed their paths.

The "whomever," it turned out, was a stooped older gentleman with a smartly trimmed beard, piercing brown eyes, and liver spots on his forehead. He stood near a featureless door with his hands clasped behind his back. He wore a white robe with a caduceus embroidered over his heart. Credence supposed he must be a doctor.

"Auror Goldstein," the man said by way of greeting. He cocked his head in Credence's direction. "Is this his… next of kin?"

"This is Credence," Tina said. "He's the ward of Mister Graves."

The man's expression went very solemn as he nodded. "I'm sorry, son. We've done what we can, but I'm afraid he may be too far gone. The only thing we can do now is wait."

"What do you mean?" Credence blurted out. "He's. He's a vampire. All he needs is a little blood, right?"

"If these were normal injuries, perhaps," the gentleman with the sad brown eyes. "Or if they weren't so grievous. He's close to a blood frenzy. We can't risk letting anyone close to him because they won't survive."

The statement hung in the air between the three of them, heavy and final in a way that Credence could not bear. Tina's hand came to rest on his shoulder, but he shrugged it off. A cold certainty coalesced where his unease had started to take root. "Let me in there," he said. "I can. I can help him. I can give him some of my blood and keep him from hurting me."

The man's brows shot up. "Son, when I started practicing the healing arts, I took an oath to do no harm. Letting you into that room when he's on the brink like this? That'd be doing some harm to put it lightly. I can't let you do something so crazy."

"It's not crazy," Credence said. "I'm…" Not human. A monster. Strong enough.

None of the words came out. Instead, he turned to Tina and fixed her with what he hoped was an obstinate stare. "I can help him, Tina. I know it. You didn't bring me here just to sit by while I could help. Let me do this." He poured all of his certainty, all of his need to help, all of his wanting into his words. Willed Tina to see his strength that he'd built. To see he was not weak.

She returned his gaze, unflinching, and his heart tripped over itself. Please, please , he thought, please, don't. He kept his hands at his sides, refused to fidget or fiddle with his shirt cuffs. His breath lingered, caught by the lump in his throat. Please.

The moment stretched, then broke as Tina nodded once. "You're right," she said. Credence sucked in another breath, letting his fingers find the loose thread on his sleeve that he'd never gotten around to fixing. Tina turned to the older gentleman standing by the cell door. "Listen, I know it sounds crazy, but I promise you: this young man is Mister Graves's best hope at survival."

The doctor—no, they were called mediwizards—on duty scowled and pushed his half-moon spectacles up his beakish nose. "This is highly inadvisable. If he's not already in a blood frenzy, he will be as soon as he scents living human flesh. He's more feral animal than man."

"I'm not human," Credence stated. His voice didn't shake, which was a small miracle he made note to thank God for later. Once… once he was home. Once Graves was safe. "I can…" He halted, unsure of how to proceed. Finally, he settled on, "I can keep him from hurting himself. Or me."

"It's our only shot at stabilizing Mister Graves," Tina said, resting one hand on Credence's shoulder in solidarity. "You said it yourself, if he doesn't get fed soon, he might not make it." The older gentleman looked like he was about to protest, but Tina cut him off. "Listen, with Mister Graves incapacitated, you're currently speaking to the acting Director of Magical Law Enforcement—" Credence tried not to choke on his own tongue at the bald-faced lie, managed to keep silent somehow, "—and I am ordering you to let Credence into that room."

The mediwizard frowned, but he made no more motion to object. "Of course, ma'am." With a flourish of his wand, the heavy locks that kept the door barred undid themselves before Credence's eyes. Even in such a dire situation, he still couldn't help but be a little awed by magic being worked around him.

"I can't guarantee your safety, son," the mediwizard said. "Are you sure you want to do this?"

"Yes, sir," Credence said. He didn't wait for the gentleman to respond, just shoved the cell door open far enough to slip inside before he lost his nerve. The sound of it clanging shut behind him lent an unsettling finality to the situation. Whatever happened, he knew in his bones that they were either both getting out alive, or neither of them were.

The room was dark, and it took a moment for Credence's eyes to adjust to the dimness. His eyes skimmed over the outline of a chair, an end table, a cot. There were no windows, no other doors but the one at his back, and the only wan light came from a sconce mounted high on the wall above the end table. It shed a ghostly, silver glow like that of the moon through fog. It was barely enough for him to see Graves: a disheveled, unmoving shadow huddled in the opposite corner of the room.

He crept forward, one hand outstretched, eyes focused on Graves's face. "It's me. Credence. I've come to help." Graves made no noise, no move to come closer, but he didn't seem interested in fleeing, either.

Credence took that as a good sign. "Mister Graves?" He inched closer, heart pounding in his ears. Every fiber of his being vibrated with his fear, with his worry. What if he was too late? What if Graves was too far gone? What if—

In his moment of distraction, Graves struck. One second, Credence was approaching him like he were a wounded animal. The next, Graves had him pinned to the wall next to the bed. Credence hit the wall with enough force to knock his breath out of him with a startled huff, but not enough force to hurt.

Graves kept his grip firm, but—again—not so firm as to hurt. He favored Credence with a look that was appraising. Predatory. But he didn't move.

Fingers trembling, Credence raised his hand to touch Graves's cheek. The skin was so cold against his knuckles that he shivered. "Mister Graves?"

As if time had slowed down, Graves turned his head until his nose brushed against Credence's wrist. He didn't need to breathe, Credence knew, but he felt a stir of air as Graves breathed in, then out. Taking in his scent, he realized. Deciding if I smell good enough to be eaten? They'd said that he was feral, that he would attack anyone that entered his cell, that he would potentially kill them.

And yet, here he was, nearly nuzzling Credence's wrist like a cat. A part of him wondered what that meant. A part of him suspected he already knew.

He let out a shuddering breath. "Mister Graves." He uncurled his fingers and laid his palm flat against Graves's cheek. "I'm here," he added, throat feeling suddenly dry. "I've got you." The only response he received was a rumble deep in Graves's chest, followed by the man—no, the vampire—releasing his arms and pulling him closer.

This close, Credence could feel the vibrations of the sound. It wasn't quite a growl, but it was close. He could also smell the metallic tang of the blood that must surely have soaked through Graves's clothes. How much belonged to him and how much belonged to someone else, Credence didn't know. Didn't want an answer.

He saw the way that Graves's eyes shone in the dark; the glint wasn't predatory at all, now. There was pain in them, and a wildness. But underneath it all, the best word to describe the look on Graves's face was protective . He looked at Credence as if he were something precious. Tina's words drifted back to him: He would never be disgusted by you. Anyone with eyes can see that. But they had been hard to believe when Graves had turned him away.

It was hard to argue now. The doctor—mediwizard—had emphasized how dangerous Graves would be, but his first instinct even in this state wasn't to harm Credence at all. Of course, that made Credence's mission a little more difficult.

"Mister Graves," he repeated, "You have to feed. I'm here to help you. I won't let you hurt me. Just…" His words petered out. Graves did not appear to be listening. Instead, he leaned forward and rested his head against Credence's shoulder as if he were winded.

This… This was a problem. Credence let his fingers find the back of Graves's skull and run over the short-clipped hair there. Some of it was tacky with a substance Credence could probably guess but still didn't want to name. Graves made a noise like a sigh.

Credence used his free hand to fumble with the top two buttons of his shirt until, finally, they came undone. "Mister Graves, please." He tugged his collar open to expose the area Graves had fed from before. "Mister Graves." Still no response.

Finally, Credence turned to rest his lips next to Graves's ear. He took in another shaky breath. It felt like he was about to cross a line, break some taboo that somehow felt so much larger than everything else that had brought him to this point. The point of no return. Voice barely more than a hoarse whisper, Credence murmured, "Percival. Please."

The response was immediate. Graves—Percival—snapped to attention, his eerie gaze fixing on Credence's face. He may not have been fully in control of his faculties, but Credence knew without a doubt that he was finally listening. The weight of his regard was almost too much, but Credence reminded himself, you asked for this.

Credence tilted his head to one side. Exposed the long line of his neck. Lifted his brows in what he hoped was an inviting way. Willed with every ounce of himself that Percival would understand and accept his offer.

Slowly, deliberately, as if drawn by an unseen magnetic force, Percival lowered his head to Credence's throat. When Percival's lips met skin, there was no hint of the savagery the mediwizard had promised, only gentle caution. Credence held his breath, held himself still, held tight to the monster that surged up at Percival's touch. An eternity passed. Everything was still. Everything was silent save for the frantic thudding of Credence's heart.

Then a growl, too urgent and possessive to be put into words, and Percival's fangs slid into the flesh of Credence's neck as smoothly and sweetly as if they'd been there all along. Credence made a hiccuping noise between a gasp and a sigh, and his knees buckled as the pleasure rolled over him like warm fog. He made a weak attempt to catch hold of Percival's tattered waistcoat before he dropped to the floor, but his fingers found only air.

His feet lifted off the ground. Strong arms hauled him up, held him flush against Percival's chest while Percival's mouth worked at the punctures on his neck. The world glazed over, painted in soft grays and muted blues, and then Credence realized they were on the cot with his legs slung to either side of Percival's hips and Percival's hands pulling him so, so close. Credence's fingers finally found purchase near Percival's waist, and he shoved aside the waistcoat in favor of clutching at the shirt underneath. Percival's hands responded in kind. One found its way into Credence's hair and curled into it, not quite tugging but very near. The other held him fast at the small of his back with one thumb hooked in the waistband of his trousers.

His heart pounded, his breath came in shallow gasps that kept time with his pulse. Warm, syrupy pleasure washed through his head, lessened the grip he held on himself even as it tightened his grip on Percival.

He shuddered, and, as if in response, Percival pulled away from his neck long enough to fit Credence even more tightly against himself before bending down to slide his fangs into his sensitive flesh again, more fervent, less gently this time. The pleasure seared through Credence like lightning, tore an almost animal sound from his throat. He felt himself blur as his obscurus rose to meet Percival's fervor.

The edges of Credence's vision gave themselves to dark tendrils of smoke, which curved toward Percival as inevitably as a flower curves toward the sun. He didn't feel it, exactly, not the way he felt his limbs, but he could sense things through the smoke. As more of him bled off into inky wisps, he found he could explore every inch of Percival unimpeded. If the man noticed the way the darkness curled around him, he was too preoccupied with Credence's throat to care.

The obscurus didn't dampen the pleasure of Percival's bite, but it gave a little distance. Instead of being subsumed in it, Credence could sink into it and then move back to take in what his other senses now told him. Through his extended self, he took the measure of the damage that Percival had weathered: the worst was the deep puncture on his right side, gaping but oddly bloodless; the skin on his back was burned beyond recognition, though Credence couldn't tell how deep the damage went; his scalp had split open near the base of his skull, and this wound still oozed a little tacky blood as dark as Credence's own.

Percival drew back, letting the obscurus caress his face, his hair, down his neck. Without looking, Credence knew his blood, thick and black like his obscurus, would be smeared on Percival's chin. At some distance, he knew he was lightheaded. Much more blood lost and he might be in danger. But his gentle exploration told him that Percival wasn't quite out of the woods. His obscurus could sense the flesh knitting itself together using the power from Credence's blood. Knew that there was still so much more work needed below the surface.

Percival sank his fangs in again with a fierce, triumphant snarl that sent ripples of ecstasy through Credence and his obscurus. The smoke shivered as if disturbed by a breeze before coming back to itself and wrapping tighter around Percival in a mirror of the way he'd pulled Credence close not long before.

There would be no way for Credence to do anything if he let Percival take too much of his blood. "Percival," he managed to say, voice cracking on the last syllable.

The response was slow, but Percival eventually pulled away a final time. The hand holding Credence's head went to Percival's chin. He wiped away the blood and licked it off his fingers with an almost distracted air. As if it were just an absent motion while he waited to see what Credence would ask of him next.

What would Credence ask of him? The distance that the obscurus provided him may have shielded him from the worst of the toll so much blood loss had, but it did nothing to clear his head. He was, in many ways, almost as much a creature of instinct as Percival seemed to be.

Credence's hands drifted up and skimmed over Percival's sides until his fingers—his human, physical fingers—found where the edges of Percival's wounds should be. He hesitated, caught between two moments. Two courses of action: disengage, get the mediwizard to let him out of the cell, wait to see if it was enough; or see this impulse through, wherever it might lead.

It was foolish to think there was a choice. Either we both get out of this alive, or neither of us do. He breathed in, closed his eyes, and let go.

His fingers dissolved as he surrendered this part of his physical form to the obscurus's magic. It flowed over Percival's wounds again, but this time its intent was far less innocent than mere exploration. The darkness pooled, coagulated, coated, seeped. He felt Percival shudder. Heard himself make soothing noises—"Shh, it's all right, I've got you…"—until the body underneath him stilled. Credence's darkness seethed and bubbled and roiled, and he waited for some sign.

When his obscurus's magic—his magic—sparked, it nearly sent Credence reeling. Flecks of red light like fire and brimstone swam across his vision, though whether they were just an illusion or actually floating within his own smoke, he could not tell. He remembered to breathe, which made weathering the next surge of power easier. The red lights like embers were definitely not just artefacts in his vision. They burned in time with his heartbeat. His magic ebbed and flowed and then caught fire as it latched on to Percival's own. Like called to like. Whatever made Percival a vampire recognized Credence's obscurus as its kin and it drank greedily from that red-flecked darkness.

It was like when Percival fed on him, but purer without something so inelegant as flesh getting in the way. There was no distance from this, no filter. It took every ounce of Credence's self-control to hold himself in his own skin. But unlike his blood, the well of his magic was deep. He knew there was no chance of Percival draining it dry. So he slumped forward, rested his forehead on Percival's collarbone, and let him have his fill.

He came back to himself some time later, just a young man with plain flesh. Percival had tugged Credence's collar aside and was licking the wounds that he'd left on Credence's neck to make sure they were closed. Credence shivered. Wondered if his blood had stained his shirt. Wondered how awful they looked. Realized that he didn't care. He let his fingers explore where Percival had been injured and felt relief when he encountered nothing but smooth, cool skin. He sighed, half in relief and half in exhaustion. "You're safe now," Credence whispered into the fabric of Percival's shirt.

Percival didn't vocalize any sort of response, but he shifted his hold on Credence so that he cradled him close to his chest. As if he were assuring Credence of the same thing. Perhaps the feral edge hadn't worn off enough for Percival to form words, but he could still make himself plain in this way.

Chilly but content, Credence drifted off in Percival's arms.