“Enough,” Callum said firmly, one hand on Greyson’s chest, the other held up toward Lira. “Both of you. This isn’t helping.”

“She betrayed me,” Greyson snarled.

“She saved your life, dumbass,” Callum countered. “Even if the method was shit, the intention was good.”

“I don’t care about intentions—”

“Yes, you do.” Callum pushed harder against Greyson’s chest, forcing him back a step. “You care because she’s your sister and she loves you, and she was terrified of losing you. Just like we all are.”

The fight went out of Greyson as quickly as it had come, his shoulders sagging.

“I don’t know if I can pull this off,” he muttered. “I don’t know how long I’ll last in that apartment without killing her.”

“Then we fix it,” Callum said simply.

Both siblings looked at him.

“How?” Lira asked, her posture softening.

“Sit,” Callum ordered, gesturing to the leather chairs arranged around a low table. “Screaming at each other won’t solve anything.”

To his mild surprise, they obeyed. The siblings settled into chairs across from each other, the tension between them still palpable but slightly diminished.

Callum crossed to the bar, pouring three glasses of whiskey. He handed one to Greyson, who took it mechanically, and offered another to Lira. This one she accepted with a nod of thanks as Callum leaned against the ledge of his desk across from them.

“We get her on our side. Your father isn’t wrong that she should be used as an asset, just not his asset.” He took a sip of his whiskey. “Let’s be methodical about this. What do we know about her habits? Vulnerabilities? Weaknesses?”

Greyson’s laugh was bitter. “We’ve been living together for less than twenty-four hours. All I know is she drinks more vodka than any person I’ve ever met, has no respect for privacy, and can take a fucking beating. She’s strong, it would be stupid to underestimate her.”

Callum nodded. “So, the baseline is this—you want to kill her because she’s a Daggermouth, and Daggermouths killed Brooker, and she wants to kill you because you’re . . . well, you’re you. Is that right? Am I missing anything?”

Greyson sucked his teeth at the small hint of sarcasm in Callum’s voice. “No,” he gritted out.

“I’m going to state this plainly, and I know there are underlying factors to your role and why you do it, so don’t rip my head off. She has every reason to hate you, to hate the Serel family. But specifically you, for what you do on that platform.” Callum paused, gauging how his words landed, testing the waters before he spoke more truths.

When Greyson didn’t respond, he continued.

“I understand why she wants you dead. If I was from the Boundary, if I didn’t know you and only saw the man on the platform pulling the trigger, I would probably feel the same as her. You have every reason to hate her as well, for what Daggermouths did to your brother. But you don’t know that it was her, and this may be your opportunity to finally get the name of his killer.”

Greyson’s head slowly rose, his chin tilting up to meet Callum’s eyes. “What are you saying?” The question had the same sharp edge of a threat.

Callum leaned forward, setting his whiskey glass down on the table between them with a soft clink. He met Greyson's eyes, holding his gaze steady. “I’m saying you need to learn to live with her, at least for now. Get close to her. Get her comfortable enough to share what she knows about Brooker, about Jaeger. Then we publicly out her for turning on the Daggermouths and being part of the scheme to bring down the Serels, to bring down the Heart.”

Greyson considered Callum’s words.

“Maximus will have no choice but to execute her when that information is made known, and both your problems will be solved. You’ll know who killed Brooker and you’ll be released from your Vow to her.”

Lira leaned forward, her elbows resting on her knees as she turned to Greyson. “It could work. If we play this right, it’ll make her a liability, back Father into a corner.”

“Outside of the Daunts and the Veyra, does anyone in the Heart know who she is? That she’s a Daggermouth or that she tried to kill him?” Callum asked Lira.

Lira paused for a moment, as if she was sifting through thoughts. “No, I don’t think so. As far as I’m aware, no one outside the inner circle, and the highest ranking Veyra knows there was even an assassination attempt.”

“What about the prisoners she was locked up with?” Greyson asked, an edge creeping into his voice.

“Dead,” Lira answered quietly. “Either killed in the prison yesterday or . . .” She trailed off, but they all knew what went unsaid.

Or Greyson would be putting a bullet in their skull on that platform before they could tell anyone.

Callum nodded slowly, pushing the thought from his mind as the pieces began clicking into place. “Good. We need to keep it that way, this secret gives us power too.”

Greyson drained the rest of his whiskey, then set the glass down. “And what happens when the Daggermouths see her with me? When they refuse to believe she would willingly take the Vow or turn on them, and start an uprising?”

A valid concern, Callum had to admit. Callum had worked with many of them over the years, when procuring items off the black market for his clients. Jaeger’s assassins were fiercely loyal to their own. The idea of one of their best operatives not only failing to kill her target, but marrying him instead, would be met with skepticism at best and violent retribution at worst.

He drummed his fingers against his thigh, mind racing through contingencies and potential pitfalls. “We’ll cross that bridge if it comes to it,” he said finally. “But if we do this correctly, she’ll be dead before they can mobilize.”

Greyson’s jaw worked and Callum watched as he turned the plan over in his mind.

“So what now?” he asked, not bothering to hide the bitterness in his tone. “I just play another role, pretend I actually want to get to know her? That I’m some doting fiancée and not imagining all the ways I could end her life every time I look at her?”

Callum’s head tilted, studying Greyson’s face through the slits in his mask. “What does she look like, anyway? Objectively. Is she attractive, at least?”

Greyson didn’t respond, just stared at him with that flat, unreadable expression he’d perfected over the years. The one that could make even the most hardened Veyra officer’s blood run cold.

“I haven’t noticed,” he finally answered.

Callum’s smile turned knowing. “Sure you haven’t. Well, try to notice. Might make playing the role a bit easier if you can find something appealing to focus on. Just be careful, Grey. Don’t go falling for your fake wife.”

Lira scoffed at the statement as Greyson grimaced, disgust twisting his features. “I’d never touch a Daggermouth.”

“Good. Then this should be simple. Make her trust you. Make her think you’re on her side, that you’re falling for her and understand her hatred for the Heart. Get her to confide in you about the Daggermouths, about their operations, their contracts. If you can get her talking, she might let slip information about Brooker’s killer.” He kept his voice casual, as if they were discussing the weather and not a plot to manipulate and destroy a woman.

“Fine,” Greyson finally sighed after a long pause. “I’ll do it. But if we’re going to sell this, I need you to come back to the apartment with me. Help me clear out my father’s surveillance, we need the place clean if I’m going to make this convincing.”

Callum nodded, pushing off the ledge of his desk and stretching his neck to ease the tension that had settled there. “Let’s do this. The sooner we get this done, the sooner you can start working on your little Daggermouth wife.”

He needed Greyson focused, not constantly looking over his shoulder wondering what his father might overhear.