Theta Curry IV was a dull rock of a world. They set down on sea of grey scree deep in a valley that had once sheltered a refugee settlement from the elements. High winds buffeted the Uther Pendragon on the descent, promising vicious chill if one climbed the cliffs, and even Dathan Tahla had to wonder why this world had been chosen as a home for the most desperate in the galaxy.

But all great powers had those they didn’t care about. Even the vaunted United Federation of Planets.

‘Keep sensors focusing on ships coming into the system,’ she reminded Rhade as she slung on her gear before the lowered landing ramp. ‘The coast seems clear, but we don’t want company that might be the Rebirth.’

He nodded, frowning. ‘And don’t contact you unless I’m certain we have trouble.’

‘I don’t want to spook him.’ She tightened the last strap, looked up at him, and hesitated. ‘Like I said, it might be difficult to convince him to come back with me. Give me a day before you start to worry.’

‘I’m afraid I must disappoint you there; I’m already worrying. But you have a day until I act on it.’

Dathan’s throat tightened at not just the concern, but the simplicity with which he admitted to it. Soon she would be in a world where bonds were a vulnerability, and if they were expressed at all, they were couched in codes and subtext. Here, all she felt were his dark eyes locked on her with open unease.

The kindest way to repay him, a quiet voice reminded her, is to make sure he stays far away.

‘I’ll make contact if anything goes wrong,’ she said, trying to sound firm, but confident. If she made him feel his concerns were being addressed without promising anything concrete, he would wait. If he waited he would live, and that meant she’d never see him again.

As with Carraway, she knew if she said anything else, it would disrupt the delicate balance. Anything worthy of an eternal parting would risk being too heartfelt, which risked making him suspicious, risked making him pay closer attention to the meeting than she could afford, and that meant she’d have to kill him.

But Carraway hadn’t known there was anything odd about her mission, while Rhade at least knew there was some danger. Or that was what she told herself when she stepped forward and reached to clasp his arm before she could stop herself, gaze locked on him. ‘Thank you.’ For everything.

The corners of his eyes creased as he watched her. ‘Be careful.’

It was not enough, and yet it would have to do. Even another heartbeat of looking at him would be too much, and still it felt like something wrenched in her as Dathan turned away from him and disembarked from the Uther Pendragon.

Those were her last words as Lieutenant Dathan; this was her last act under the guise of the Starfleet officer, the colleague, the friend. As her footsteps crunched across the rocky surface, every step took her further and further away from the mask, from the lie, until finally she moved through the jagged wasteland and the runabout, and Rhade, were both out of sight.

It was over. She was her again. And yet the weight on her shoulders had not lifted.

Once you’re underway, it’ll be different. You still need to get off-world without drawing suspicion. Without having to put him down.

She had picked a landing site close enough to the meeting coordinates she could travel on foot, but far enough that Rhade could not easily catch up if he got it into his mind to follow. So she travelled for an hour, supply pack slung over her shoulder, rugged away team gear keeping her warm against the occasional gusts of chill wind that slipped through the valley’s protection to buffet her.

After a decade and a half, there was not much left of the refugee shelter the Federation had built and then abandoned. The settlement had collapsed over years, Romulan refugees taking anything of any value with them, usually to buy transit off-world. From a distance, the camp at least bore the silhouette of a settlement, offered the shadows of rooftops and shelter. But soon she walked through a ghost town, through nothing but the husks of prefab buildings stripped of walls and roofs for metal, or battered and broken by the elements.

The wind whistled more down here, in this open stretch of the valley big enough for the shelters, and Dathan repressed a shiver. No wonder the refugees had left once the support stopped. Teros had been unwelcoming, but it had been bigger and more self-sustaining, and for all its inhospitability as an environment, it had not felt like a graveyard of a world.

Amid the shadows of a shelter that had brought no succour, Dathan drew her tricorder, consulted it for the lone life-sign within a hundred metres, and made for what transpired to be one unremarkable, run-down prefab building among scores.

The sun on Theta Curry IV was a weak, anaemic thing, already tired by a long day and so in no state to pierce the shadows of her target’s shelter. Detritus crunched under her boot as she stepped through the doorway, phaser already in hand, eyes sweeping the collapsed remains of what had once been a home for the desperate.

One shadow moved, or so she thought, but it was from the opposite side of the room that a figure stepped out of darkness. ‘If you call me Heorot,’ a low voice rumbled, ‘do I call you Beowulf or Grendel?’

Dathan’s jaw tightened at the familiarity, but instead she said, ‘This is a terrible code. They do have Beowulf in this universe, you know. Of course I’m not going to call myself Grendel if I’m on your side. And I thought Heorot was a place, not a person, Kowalski?’

She’d last seen Tom Kowalski three days ago, down in Endeavour’s gym. The big master-at-arms had always been dedicated to his fitness, but that commitment had increased tenfold as he’d recovered from the back injury he’d taken at Jhorkesh. While the figure before her shared his build, his square jaw, his craggy features, this was not him.

Her universe’s Tom Kowalski levelled his phaser at her. ‘We’ve never met.’

‘And yet your counterpart is on the USS Endeavour. Apparently parallel universes have a sense of humour. Or destiny.’ She did not lift her weapon, and not just because he had her at a disadvantage. ‘Agent Dathan, reporting for extraction, sir.’

Kowalski didn’t move. ‘You’re MacCallister’s creature, reports say. What painting’s on the wall in his office?’

‘Vercingetorix Throws Down his Arms at the Feet of Julius Caesar, by Royer.’

‘It’s by Motte.’

She made sure to not snort. ‘That’s Vercingetorix before Caesar. Different painting. His is Royer. Have you ever been in MacCallister’s office, or did a superior give you that to test me?’

Kowalski lowered his phaser, expression not particularly changing. ‘They said you always had a wilful streak. The Federation made you uppity.’

‘I’m the most successful infiltration agent Endeavour’s ever had. I’m the only one who lasted more than three months before getting my cover blown, or being forced out before that could happen. Being good made me uppity.’

‘Yeah. Seems you’ve done alright for your kind,’ he grunted, and turned away to where a bag was nestled in the corner. ‘Assume you came alone?’

A tension settled in her throat. ‘It’s just me here. Why has this happened now?’

Kowalski hefted his bag and frowned at her. ‘I thought you’d be happy to get out of deep cover.’

‘My happiness is irrelevant. I’m well-embedded. I have the trust of the crew and their Rourke. I don’t understand why I’m being pulled when I’m still more use as an agent on the USS Endeavour than on the ISS Endeavour.’ Doing whatever my role will become there. She’d been deemed a specialist by MacCallister some years ago, an analyst and adviser unbiased, in his judgement, by the political filters of most imperial officers. These were not qualities anyone else appreciated, and she knew she’d made enemies of officers whose plans, proposals, and analyses she’d recommended against. Or even ones she’d approved of but MacCallister had opposed; she knew that, by his design or otherwise, his subordinates made her an easy scapegoat when he made decisions they disagreed with.

‘You’re leaving because orders say so,’ Kowalski grunted. ‘You don’t get to debate it.’

‘So you don’t know.’

He met her eyes, gaze warning. ‘My job is to bring you back. I know you like questioning orders, seeing as you messed with Commander Rourke’s plan to blow your whole wretched ship up.’

‘Prefect MacCallister didn’t order that operation. I was protecting my mission,’ she said, letting her voice fade to a dull report.

‘MacCallister didn’t override him, though, did he,’ Kowalski sneered. ‘You’re not an operations leader. You’re not an officer. You’re MacCallister’s little pet who just happened to have a doppelganger we could replace with you. Skill and talent didn’t get you where you are, and they didn’t give you the right to question the judgement of your betters. You have forgotten your place, haven’t you, Bajoran?’

When the ISS Endeavour found itself trapped in this universe, they had done all they could to learn of their counterparts. It had been essential to know which among their crew could move freely as they sought the resources and means of returning home. She had not been sorry to see Erik Halvard leave on the Wild Hunt mission, incapable of acting freely when his counterpart was dead. But she had never dreamt of the opportunity that came when MacCallister said they’d identified her doppelganger, a lowly intelligence analyst she could easily replace.

It hadn’t felt like freedom to leave her Endeavour and enter a world where the slightest mistake would mean, she’d assumed, death. She’d ached for the reliability of her old life, where she knew what she was supposed to say and what she was supposed to do; where the sneering racism was part of the fabric of the everyday, sliding off her skin like silk. But after so long away, Kowalski’s words itched.

Dathan took a slow breath and reached deep within herself, where old habits and masks lay, as simple and familiar as breathing. ‘No, sir. Sorry, sir,’ she said with a meekness she didn’t feel.

Even when you’re among your own people, you’re lying.

The thought almost stole the breath from her, the air rushing in her ears. Kowalski said something she didn’t process, then reached into his bag and pulled out a tricorder. Something in her screamed to stop him, to distract him, but when she stepped forward, the ground felt unsteady underfoot.

Then he read his tricorder, looked up at her with a frown, and the world came rushing in as he said, ‘That’s your ship a few klicks out? There’s someone aboard. I thought you said you came alone?’

‘I don’t…’

Kowalski flew across the distance, his grip iron-right as he grabbed her shoulders. ‘You stupid bitch, you brought someone with you?’

‘Starfleet protocol – the captain wouldn’t let me -’

‘Then why didn’t you fucking say?’ Kowalski pushed her back roughly, then ran a hand through his hair with a hissing breath. ‘Who is it?’

Words were acid on her tongue. ‘Adamant Rhade. Hazard Team leader.’

‘So what passes for a fighter in softie Starfleet,’ Kowalski sneered. ‘Right. Call him. Tell him to come out here, and we’ll kill him before we go.’

‘He’s at least an hour out,’ Dathan scrabbled. ‘I’ve told him I could be gone as long as a day; we can get to your ship and be far away before he even suspects.’

He stared at her. ‘What kind of rookie op have you been running, Dathan? If he comes looking in a day and you’re gone, he raises the alarm. But your ship won’t be expecting you for, what, thirty-six hours? Then assume they won’t instantly panic, and have to get here, so that’s at least another day before anyone arrives looking for us. Putting aside if he doesn’t sit tight, or he notices our ship leaving and gets suspicious. Someone follows us, that endangers the entire ship.’ Then he rolled his eyes. ‘Screw it. We’ll head out there, kill him, and you can make sure the shuttle sensors don’t even pick up us leaving. Leave no trail.’

Dathan straightened as his words thudded into her. ‘You’re right,’ she said at last. ‘If you take up position nearby, I can lure him into the open and you can get the drop on him. Then when he thinks I’m not the threat, I’ll take him out.’

Kowalski gave his first real smirk, gave the first softening of his scowl. ‘You had me worried for a moment, Dathan. I read your record before coming here – you supervised the Talipol Purge, you executed prisoners on the prelate’s behalf, you hunted down the dissident on Trill. And here you were making me think you weren’t still a born killer, that you’d gone soft. Good plan; let’s move.’

He reached into his bag and pulled out a rifle, which he slung over his shoulder before he turned away and tossed the bag down. And the window of opportunity made the decision for her.

She did not simply raise her phaser in one smooth move and open fire. Because first she thumbed the power setting up as high as it would go. Kowalski didn’t have time to so much as scream, likely knew nothing but instant oblivion as the phaser blast hit his back, killing him at once and vaporising the body a split second later.

‘You’re right.’ Her hushed voice hummed off the walls, lingering more than the hiss of phaser fire. ‘I’m still a killer.’

And in the silence that followed, filled only by her own shaking breath, she did nothing but stand and stare, because she knew she hadn’t just killed Tom Kowalski, but Dathan Tahla, too.