A one-fic bingo for MAS bingo, combining the prompts broken + revenge + ghosts + detective partners + "I want to be a monster that helps people". It is Lovecraft inspired and it is not happy.

Ace compares the circle on the ground with the one in the book one more time. It's perfect, as it should be-he spent a long time measuring angles and using protractors to make it as precise as it needs to be. He snaps the book shut and stands in front of the circle, looking down at it.

He's gonna get one shot at this, he knows, and any distraction will cause untold destruction. He takes a deep breath, closes his eyes, and concentrates. It's just there, and he just has to reach for-

"Ace! What have I told you about summoning in the living room?"

Ace's eyes fly open and his shoulders go tight. "Sabo," he says, trying to keep the flow. "What are you-"

"At least you rolled up the carpet this time, but this isn't chalk, is it? Oh, ew, is it blood?"

Ace closes his eyes and sighs, feeling something far away and very close snap.

"You're getting it out of the floor, you know. I'm not losing our security deposit just because you got art-happy without any ink around."

Ace turns around and there's Sabo, laying his hat upside down on the console and stripping off his gloves to drop inside. "Sabo," Ace says again. "I wasn't expecting you so soon."

"Obviously," Sabo says, wandering over closer to look over Ace's shoulder. "Huh," he says, and then falls quiet for a minute, then says, "That's some really neat work."

"Yeah," Ace says, because it took him ages to get the circles mashed together into something that might work, and even longer to paint it out.

"That price, though," Sabo says, and whistles "You sure about that?"

Ace rounds on him. "Any price is worth it, you know it is."

Sabo just shakes his head and looks it over one more time. "Shame about it, really," he says and then he walks right across it to get to his desk, stooping to pick up the dagger in the center and tucking it into his belt.

"Your fault-" Ace says.

"So what'd I miss?" Sabo asks right over him. "Any new cases, or are we still broke and unemployable?"

"Just the one," Ace says, settling against his desk to better stare at his interrupting partner.

"Oh, Ace," Sabo says, and the pity is heavy in his voice. "You're not really-"

"Of course I am," Ace says, locking eyes with him.

"Still? Hasn't it been months already?"

"Of course," Ace says, gesturing widely. "I can't just-I don't know how you're over it-"

Sabo shrugs. "You're just stressing yourself out. The guy's disappeared-"

"I've got a lead."

"It's over and done with."

"It's not over! It'll never be over-"

"You don't even know his name!"

"I do," Ace shoots back. "I haven't been just sitting around sulking without you-"

"Really?"

"Contrary to your opinion, I am not utterly useless on my own!"

"You sure about that?" Sabo asks, but he's already in front of Ace, reading the file in his hands upside down. "Huh, is that him?"

Ace blinks up at him. "You don't recognize him?"

Sabo hums noncommittally, leaning in, and Ace takes a second to just revel in the comfortable annoyance that Sabo has always inspired in him. "I missed you," he says.

Sabo glances up at him from where he's leaning and blinks at whatever he sees on Ace's face. "Hey," he says, reaching up to rest his hands over Ace's. "Hey, it's okay. I'm back now."

Ace's fingers tingle a bit under Sabo's, and he clenches them tighter. "And you're not leaning again, right?"

Sabo smiles a bit and raises one hand to Ace's cheek. "I couldn't even if I wanted to," he says, and his grin is the sharp one that shows teeth. "You know that. I'm here, Ace."

Ace closes his eyes and shudders out a breath, leaning into the feeling of Sabo's hand against his face. "Okay," he says, then takes a breath and tries again. "Okay."

"C'mon," Sabo says, and Ace's knees give out. He slides down til his back is against his desk, leaning his head on his knees and sobbing out all the pain of the past few months, for all he's lost and all he hasn't. Sabo sits with him and murmurs comfort until he's all cried out.

He runs out of tears surprisingly quickly, and looks up into eyes more familiar than his own.

"You good?" Sabo asks, sitting back on his heels. "Haven't cried since then, have you?"

Ace shakes his head, reaching into his pocket for a handkerchief, and the sight of it makes Sabo huff a laugh. "Really? You kept that old thing?"

"'A handkerchief is a gentleman's best friend'," Ace quotes, and then blows his nose loudly.

"You're such a dork," Sabo says, and a shiver goes down Ace's spine at the familiar words. Sabo's smile is soft as always, but his eyes aren't.

"Yeah," Ace says, holding his gaze. "Yeah, I guess I am."

Sabo nods, then stands up off his knees in one smooth motion without using his hands, and Ace huffs a laugh. He'd forgotten Sabo did that, how had he forgotten? He'd spent a whole month practicing when they'd been kids, banging up his knees. What else had he forgotten while Sabo'd been gone?

He pokes the part of him that holds his grief, but it's hardening over into determination. "Okay," he says, looking up. "You're the expert at finding people. What next?"

"This lead of yours," Sabo says, tapping a finger on the photo. "Start there. Where do we find him?"

Ace scrambles up to stand next to him. "We?" he asks, a lump in his throat that may well be his heart.

Sabo shrugs. "I'm not letting you go alone," he says. "Besides, seems to me I've got some unfinished business with him myself."

Ace nods frantically, already snatching up the folder. "I've got the address of his last known associates," he says, talking fast. "I think he turned on them, too, which would make it easier-"

"A rouge, huh?" Sabo muses, and his fingers go tippatap on his thigh. "A traitor, even."

Ace nods again, because he knows how Sabo feels about traitors. Then again, he's a lot less forgiving himself these days. "Allies," he says, and it's Sabo's turn to nod.

"Maybe," he allows. "What was he a part of? A gang? Drugs? "

"Worse," Ace says, pausing at the door while Sabo tugs on his gloves. "He was a cop."

"Ooh," Sabo says, flashing his teeth. "You know what that means, don't you?"

"Of course I do," Ace says, shoving his hands into his pockets and widening his stride.

Sabo's a few steps ahead, and he hums and twists around to walk backwards. "Have you seen him?"

"No," Ace says. "Not since..."

"Good," Sabo says, turning back forwards and falling back to Ace's side. He catches Ace's surprised glance and says, "Is that horrible of me? I've always been a bit jealous with you, you know."

"I know," Ace says, because he does. Sabo just used to hide it better, always catching himself before saying anything. "It's fine."

"Absence really does make the heart grow fonder, huh?" Sabo muses. They walk in silence a bit, and Ace listens to the way their boots his the ground in sync. It's soothing, just like every other time they walked this path, back when his life was still whole.

The police station is as it ever was, and walking through the front door is nostalgic in all the worst ways. Jack's on duty at the front desk, and Sabo leans on it and smiles at him, bright and wide. "Hi."

Ace steps up next to him, and Jack looks up. "Ace," he says, then swallows. "Hey, man. How've you been?"

Ace stares down at him, and Sabo stifles a mean little giggle. Jack scrambles upright and says, "I'll just-go get the chief for you. Yeah. Uh, just a moment."

Ace paces a bit, turning a well-worn path in the lobby as Sabo perches himself on a chair and tugs his hat low over his eyes.

It's not an entire minute before the quick clack of shoes on linoleum heralds the appearance of a blond ghost Ace has been avoiding for ages. His sharp eyes scan the lobby, and Ace steps forward to draw his attention.

"Detective Phoenix," Ace says.

The man takes a few rapid steps forward. "Ace," he says, reaching out one hand.

"Detective Phoenix," Ace repeats, eyes firmly on a spot three centimeters to the left of the detective's head.

His hand drops. "I'm so sorry," he says, taking one more step. "Ace, you know it's not your fault-"

Ace dips his head and thrusts out the folder. "Do you know this man?" he asks, and it's a lot less effort than he thought it'd be to keep his voice even.

"This is about how I expected this to go, honestly," Sabo comments, rocking back just a bit on his heels, and Ace ignores him as hard as he can.

The detective does too, not even looking away from Ace. "Are you okay?" he asks instead, reaching out just the way Sabo had earlier.

Ace thought he would flinch, but he doesn't. He doesn't flinch or move, just looks up and lets the detective make the next move.

He meets Ace's eyes and falters. "Ace...?" he asks.

Ace holds out the picture. "Do you know him?"

"You have to stop this crusade," he says. "It isn't healthy. It isn't like you."

And where nothing else has managed, this is the thing that lights his rapidly-freezing fuse. "Like me?" he says, and runs his free hand through his hair. "Like me."

Marco takes a half step back, and Ace pretends not to notice. "Maybe it's awful. Maybe I'm not thinking clearly. Maybe I'm doing something dumb. But it's just like me, and if you think it isn't then you never knew me at all."

"But it's not like you, Ace," Sabo says, pressing up against his back and leaning forward to glare at Marco. "It's like me."

"I know," Ace says, shrugging Sabo off. "I can't let this go. He killed my brother, Marco, and I can't even-"`

"I know," Marco says, "But Ace, he'd want you to live. Sabo-" Marco cuts off, gesturing with one hand.

"Hey, leave me out of this," Sabo says. "This is all Ace's brand of crazy."

Marco huffs a sigh, and Ace sets his chin. "I'm going through with this, Marco," he says. "I'm gonna find him and stop him from hurting anyone else."

Marco sighs. "If I help you with this now," he says, slowly, carefully, "will you come to me afterwards? Will you let me help you?"

Ace swallows. There's a sadness in the slump of Marco's once-proud shoulders and frown lines carved into his forehead that weren't there months ago. None of this is fair to Marco, he knows, but then it wasn't really fair to him either.

Ace knows it's not a fair promise to make, but he really needs the help.

"If you help me now, I'll even come back to the force," Ace says and can't even tell if he's lying.

Marco's eyes are sharp, but he nods. And why shouldn't he? Ace has never lied to him before. "Then I'll help," he says, and takes the picture.

His quiet inhale is enough to tell both Ace and Sabo that he does indeed know the man. "Who is he?" Ace asks, stepping forward, and it's Sabo who puts a hand on his shoulder.

"Give the man some time," Sabo says, eyes on Marco. "He'll tell us."

Marco's eyes flicker from the photo to them, then back again. "This is..."

"You do know him," Ace prompts.

"Yes," Marco says reluctantly. "He was a part of the Second Division. Pretty new, joined after you..."

"Yeah," Ace says.

"It's not your fault," Marco hurries to say again. "Ace, look at me-"

"What's his name?"

Marco hesitates, but he hands the photo back. "Marshall D Teach," he says. "He was a good lieutenant, well-liked, and he quit after-"

Ace nods and Sabo scoffs. "Can't even control your own men, can you?"

Marco cuts his eyes away and then back. "It really shook everyone up," he says. "You really think it was Teach?"

Ace nods tightly. "He's been looking for something. He's making quite a ruckus in certain circles and throwing around a lot of cash. I think whatever it was he was looking for-" He cuts off.

"You think...he found it?" Marco asks.

Ace nods tightly. "Yeah. And I think Teach killed him for it."

Marco eyes him, considering, and then he spins on a hell. "Jack," he snaps, loud enough to make the desk sergeant jerk upright. "Get me the personnel file for Marshall Teach."

"Yessir!" Jack yelps, already running for the Records Room.

The wait is quiet and awkward, but it isn't long. Jack's back within three minutes, handing Marco a file and heading right back to his desk on the far side of the room. Marco opens the file and skims it, then closes it and hands it to Ace, glancing away towards where Sabo is looking over the Wanted bulletin board.

Ace accepts it, and then he looks up. "Hey, about that promise I made..." Marco jerks his head around to stare at him, and Ace swallows. "I need you to hold me to it."

Marco blinks at him, once, long and slow. "Okay...?"

"I...may have done something," Ace mutters, looking down and fiddling with the cuff of his jacket. "And after this I might not be... but I still want to help people. That's all I ever wanted." He looks up and catches Marco's eyes. "So I might be...different. I might fight you. So hold me to that promise. Please."

Marco holds his gaze for a long moment before nodding.

Ace sways into Marco's space, just close enough for Marco to reach for him again, and Sabo slips in against Ace's side. "We've got to get going," he says.

Ace ignores him, turning his eyes to Marco. "I miss him," Ace admits, small and quiet.

Marco drops his hand. "Me too," he says, and doesn't try to stop them when Sabo chivvies Ace away.

Ace opens the folder as he walks, trusting Sabo to guide him. "Marshall D Teach," he says out loud.

"Interesting guy," Sabo says from beside him. "What's the file say?"

"Joined a year ago, exemplary service, in line for a promotion, no leadership potential. Looks like just your average cop."

"Until he went off the rails and killed, you mean?"

"Mmm, right up til then." Ace closes the file and tucks it into his other one, lodging both under his arm. "So, where is he?"

Sabo looks at him sideways. "Why would I know?"

"Because you always know," Ace says. "I solve them, you find them. Way it's always been, hasn't it?"

Sabo's grin is sharp, with a lot of tooth in it. "Maybe I know where to start," he admits.

"Of course you do," Ace mutters, but Sabo's already lengthening his stride and heading towards the south side. "And of course it's here."

Sabo drags him all over the south side, following some instinct Ace can't fathom. It leads them around three gang hideouts and over a meth lab and through one street tough who did not want to let them pass.

"You're doing this on purpose," Ace accuses, chest heaving as he stares down at the fellow.

"Me?" Sabo says. "Now, does that sound like something I'd do?"

"Yes," Ace says. "You've done it before."

"Have not," Sabo blatantly lies, stepping over-and on-the unconscious man. "C'mon, it's just around here somewhere."

"Are you tracking him by scent or something?" Ace asks grumpily but follows.

"Yeah," Sabo says, making a big show of sticking his nose in the air and sniffing. "Smells like...cherry pie and dirty socks." His nose wrinkles. "Not a very pleasant combination."

"Just...stop leading me into danger," Ace says, and Sabo laughs, heavy and unpleasant.

"Right down to business, sure, I can do that," he says, and ushers Ace around a corner and onto a main street. "And there he is," Sabo says, gesturing towards an opening door like he's presenting a prize.

"What?" asks Ace, looking around.

"What?" Marshall D Teach says at the exact same time, blinking, and Ace growls and pounces.

For a fat man, he's surprisingly fast, and Ace keeps his head up and his chest back and breathes deep as he chases him.

It's not a long chase, in the end; Teach turns off the main street and down an alley that's got a dumpster blocking off the back, and Ace follows.

"I'm gonna kill you for what you did to me," Ace says, and then the shadows come to life.

They swirl and writhe up from the darkest parts and wrap themselves around Teach's legs, and all his stomping and yelling does nothing. They squeeze tight and slam him backwards into the dumpster, head first, and present the lolling, unconscious mess to Ace.

"You really should kill him," Sabo says from where he's leaning casually against the wall.

"I know," Ace says, but doesn't move.

"It wouldn't even be that hard, you know?" There's a knife in Sabo's hand now, a familiar one that he shouldn't have, and he holds it out. "For all he's done to you. For all he's taken."

"I should," Ace says, not taking the knife.

Sabo crowds close and places it in his hand, wrapping his fingers around it. "Go on," he says, breath cold against Ace's neck. "Do it for me?"

And that gets Ace's legs moving. He steps forward shakily, and the things holding Teach in place twist and part to let him pass. It's easy to keep going, once he's started, though, and there's only a dull ache where his heart used to be.

He rests one hand against Teach's chest and lays the tip of the knife against the other side. It'd be so eay, wouldn't it? A quick little push, and the grief would go away. A single second and the past few months would be worth it...

"It's so easy," Sabo says. "C'mon, Ace. Isn't this what you've been waiting for? Dreaming about?"

Yes, it is, yes, but also no. He needs his revenge, sure, but he never wanted this. His hand is shaking, and he almost drops it because this isn't him, he's never killed, he wanted to help-

"The price you paid to summon me was your humanity, you know," the thing wearing Sabo's face says. "You're a monster now. No one could love someone who threw away their own heart."

"I didn't-" Ace protests.

"You did," not-Sabo says. "I broke your heart when I died, didn't I? And you thought nothing could be worse, didn't you?" Ace doesn't answer, and it's suddenly a foot taller and looming over him. "Didn't you?"

"Yes..." Ace whispers, because he really had. He'd thought he'd had nothing left to lose.

"There's always something left," the shadow-creature that has almost nothing left of Sabo in it says. "And you gave it to me. So kill him, Ace."

"I-"

"Kill him." This time the voice is everything, loud and in his head, and everything is spinning thoughts of blood and loss and the ache that Sabo left behind and- "I don't-"

"KILL HIM."

And Ace raises the dagger. His head is spinning and so is his sight, but his left hand is a fine guide, and he raises it high and plunges it forward.

There's a snap that echoes, and then silence.

Ace holds his breath, staring down at the lax face below him, and there's a looming pressure behind him.

"That was dumb," the voice says, and it's back to being Sabo's.

"I know," Ace says, and he does, is the thing, he knows, but for all he thought he was heartless, maybe he isn't. Maybe not yet.

The not-Sabo sighs and slides around to pick up the shattered pieces of the knife. "Did you really have to stab the wall?" he asks, and it must be done pretending to be human, because nothing human moves like that, or has teeth that sharp, or eyes that glow. "Look what you've done to my knife."

Ace says nothing. He doesn't think there's anything to say.

"Oh well," it says and shrugs, a long, liquid, boneless movement. "Still, you know? No refunds."

It's only his humanity, Ace thought on the long nights he'd lay awake missing Sabo. It's only his humanity, he thought when crafting the summoning circle. "It's only my humanity," he says now, and doesn't believe it anymore.

"You're a monster," it says, smiling too wide and spinning, arms out. "A monster like me, Ace."

"That's fine," Ace says. "I may be a monster, but I'll be a monster who helps people."

It laughs, loud and awful. "Keep trying. I'll see you in hell one day." And with a screeching noise that makes Ace flinch, the thing that was never his brother melts into a puddle of shadows and is gone.

And Ace is alone in an alleyway in the worst part of the city, and he sinks to his knees, stares at his hands, and tries really hard to feel anything but cold.