The corridors to the lower deck narrowed, walls half-carved from asteroid rock and half-reinforced with the battered plating that still bore the wear and tear of long years, pock-marked with dents and scorch-marks of whatever disaster had befallen this place.

‘Getting faint readings,’ called Logan from the front. ‘Energy residue all over the place, but concentrated ahead. That’s our power core.’

‘Let us see it for ourselves,’ said Torkath with a firm nod, and shouldered ahead, Brok’tan in his wake.

Kharth let them go and grabbed Logan by the elbow to draw him back a few feet. ‘Is this a good idea? Letting them get their eyes on what might be the heart of all of this?’ She kept her voice low.

‘You saw Torkath back there,’ Logan muttered. ‘He don’t trust us, and did it occur he might be right not to?’

‘I don’t care –’

‘I ain’t worried about his feelings. I’m worried that if he thinks the Empire’s being sidelined, he’ll start to act out. There’s no reason yet for this to not be an even partnership. Let’s not make one.’

‘I feel the reason of “he tried to kill us last year” is pretty good,’ Kharth pointed out. ‘Thawn and Forrester were abducted on Brok’tan’s watch – and he’s the moderate one.’

‘Then what do you suggest? Treat them like an operational hazard, sidelining them until he declares we’re hiding things from him and kicks off?’

Her jaw tightened. ‘I’d say it’s not an either-or, but you involved them in this investigation down here. So, yeah, now you’ve forced my hand. Good work, Commander.’ She shouldered past him in the gloom, the taste of bitterness even sharper on her tongue than the newly recycled air, and advanced on the doorway ahead.

Beyond a thick metal frame of an open blast door was a circular chamber. Even before she stepped through, Kharth felt it – a low vibration through her boots, like a ship at low impulse, steady and alive. The walls curved in smooth arcs of dull metal, the entire chamber sealed with panels rather than rock. Plating was crosshatched with conduits that bore the faintest pulse of slow, blue luminescence, steady as a heartbeat at rest. At the centre hung the power unit: a column of crystalline plates suspended between ceiling and floor by thick struts, its surface rippling under their torches like the surface of water.

‘There she is,’ said Logan behind her, voice low. ‘Still running.’

‘Barely,’ grunted Brok’tan, reading from his tricorder. ‘Energy output is negligible. Whatever remains from the launch of the energy pulse is stable but faint.’

Kharth lingered near the doorway, folding her arms across her chest. ‘It would have taken a massive amount of energy to do something like open that fissure. I’m surprised there’s anything left at all.’

Logan passed her to join Brok’tan before the central power unit, his own tricorder out. ‘This isn’t just a reactor or an energy cell,’ he mused. ‘I’m picking up residual interdimensional flux; tri-quantum traces bleeding into local subspace. It’s faint, but it looks like this thing’s still coupled to a pocket beyond normal space. Maybe still drawing power from there?’

Torkath wandered the perimeter and paused near Kharth, studying a console on the bulkhead that gleamed with glyphs the universal translator had not yet tackled. ‘So this is the heart of it,’ he said, tone edged with a suspicion she couldn’t help but share.

The others had explained this was built along different, more sophisticated scientific principles than the rest of the facility. Kharth could tell that for herself just from the intricate work of the conduit design, but even more striking was the construction of the interface systems and control panels: more flowing white lines on the interface, more intricate glyphs and designs on the panels.

‘Captain,’ Kharth said sharply as Torkath raised a hand. ‘Don’t touch anything. Let Cortez or Airex look first.’

His glower gleamed under the pale light of the core. ‘You think me a child, who needs Starfleet to supervise even the most basic examination of technology?’

‘I think this is advanced interdimensional technology strapped to an old mining rig,’ she said flatly.

Torkath’s jaw tightened, and she could see pride battling caution – then a glyph on the display flickered again, and changed before blaring a brighter, ominous emerald.

‘It’s active,’ he hissed. ‘Responding to our proximity?’

‘Torkath -’

‘I will not touch it,’ he said, but his tricorder came up, flaring with what looked like an attempted remote interface.

A sharp chime echoed through the chamber. The hum underfoot deepened; light rippled along the crystalline column, blue shifting towards a pale gold. Logan swore softly.

‘What did you do?’

‘Nothing!’ Torkath snapped, but the consoles were already waking, alien glyphs scrolling too fast to make out. The low vibrations rose to a growl, and dust cascaded down from the ceiling.

Then came the alarms.

Kharth barely knew what was happening before Torkath hit her. For a second, she thought he’d lashed out, blaming her, only for him to barrel them both out of the chamber and into the corridor –

Just as the blast door slammed shut behind them with a thunderous crash.

‘Jack!’ Kharth was on her feet in seconds, lunging for the sealed door, its narrow viewport flaring with bright light by now. She hammered on the panel beside it, only for the system to blat in indignant refusal.

Inside came muffled shouting, the roar of energy surging. Her wrist panel flared to life with spiking sensor readings, radiation warnings flashing red.

‘Containment’s active!’ came Logan’s voice over comms, a dull roar behind him. ‘Something’s charging –’

A new voice cut across, clearer. ‘Kharth? What’s happening?’ snapped Cortez. ‘I’m reading massive energy spikes from your location!’

‘The core’s reactivating! Jack and Brok’tan are sealed inside!’

Torkath was by her side, hands feeling around the rim of the solid door. After a beat, he drew his kur’leth with a snarl. ‘Help me, Romulan. We can force this and free them.’

She did not know if her loss of name was a dismissal, a call for them to unite despite their differences, or a presumption of her strength. She didn’t care, leaning in with him as he tried to force the blade in between the gap in the door, knowing that it would be impossible if the chamber was built with even the faintest competence.

They had made no headway when heavy boots thundered behind them, and then Cortez was there, sliding down beside the full door control panel, Airex beside her.

‘Energy’s rising exponentially,’ Airex reported. ‘But these readings – they don’t make any sense…’

Kharth had never seen him smack his tricorder before. Now he did so, as if it would unfurl the mysteries with enough kinetic energy.

Something in her gut dropped out.

Cortez looked up at him. ‘It’s gonna overload, isn’t it.’

Airex worked his jaw. ‘I don’t – I don’t know. I don’t know what this is.’

Kharth rounded on the engineer. ‘Can you shut it down from here?’

‘I can try,’ said Cortez, the panel already cracked open. Her gloved fingers flew over circuitry, bridging connections.

‘Wait!’ called Torkath. ‘Surely it is easier to force the door, get them out -’

‘And if this overloads with the door open, we all die -’

‘You are tinkering in the dark, Human!’

Then the alarms dulled. The vibrations fell to a low hum. Cortez looked up, breath catching. ‘That should do it. There was a low-level matter/anti-matter reaction going on in there, probably what’s causing the subspace bleed – I managed to scale it right back…’

Kharth smacked her comms. ‘Jack.’ Her voice quavered. ‘Come in, report.’ The viewport was so narrow she could see nothing in the gloom.

His voice came a beat later, croaking. ‘Woah. That was – we’re here. But the core’s –’

The floor heaved. Blinding gold light roared through the viewport, searing and bringing with it enough concussive force they staggered.

Then, silence.

Kharth’s ears rang. Spots danced in front of her eyes, and as she tried to steady herself, she saw Cortez already scrambling to her feet, slamming the emergency override that now answered. The bulkhead shuddered, hissed, and rose.

The light inside was gone, the room dim again, but filled with thick smoke curling venomously from the central core, now dead, still, and cracked. Somehow, Kharth pushed past Cortez to beat her inside, even as Airex shouted warnings.

Brok’tan on the floor, smouldering, motionless, his suit scorched black and split. Logan –

Logan, on his knees, gloved hands clutching at his face. As her hearing cleared, she heard his screaming.

She fell before him in an instant, grabbing his shoulders. ‘Jack – it’s me, we’ve got you -’ Behind her, she heard Cortez barking through comms to Endeavour, and she opened her mouth to give instructions, demand the emergency medical beam-out.

But all words died on her lips when Logan’s hands fell and she saw the burnt-out and blackened pits of his empty eye sockets.

‘Brok’tan’s dead,’ Airex was reporting, on his feet and speaking with that firm, detached tone she associated with the parasite living in his gut. ‘Have them beam Commander Logan directly to sickbay. Now!’

It was like the ringing in her ears was louder as she clutched at him, her voice a low, desperate babble. ‘Jack, we’ve got you – we’re sending you back to the ship, you’ll be fine…’

Then the transporter light consumed him, and he vanished into the dark. She didn’t move, and for a long moment there was silence, not even the team’s tricorders so much as chirruping in the shadows.

Torkath’s booted foot on the plating echoed. Then another, and another, slow and determined, until he stood before the burnt figure of Brok’tan, and took a knee. Kharth was only dimly aware of his movement as he bent over the elderly Klingon.

Then he roared to the heavens. And when he was done warning Sto’vo’kor of the arrival of a warrior, he was on his feet and furious.

‘I told you!’ he snarled, rounding on Cortez. ‘I told you to open the door, not play with antimatter reactions in technology you barely understand, but your Starfleet arrogance –’

Cortez was backing off, and Airex faltered in the face of such a sudden, furious display. Before she knew it, Kharth was on her feet and in Torkath’s face, her grip on his EV suit white-knuckled.

‘And I told you not to touch anything!’ she roared. ‘We don’t know what that system was doing -’

‘Get your filthy Romulan hands off me -’

He shoved her back, and his hand flexed for his side – but his kur’leth was outside, abandoned on the deck. Either the realisation he had lost his blade or that he was reaching for it was enough to break his haze of fury, and Torkath took a step towards it, chest heaving.

‘You spent this mission obfuscating what you could,’ he hissed, padding to collect his blade, and Kharth found her hand resting on her phaser. ‘And then, in your arrogance, killed my second officer when he could have been saved. There will be no answers here, will there?’ He retrieved his sword, and for a moment, he hesitated.

Then he sheathed it and spat on the floor. ‘But there will be a reckoning.’ Torkath smacked a button on his wrist panel, spat a command in Klingon – and was consumed a moment later by crimson transporter light.

Fury spent, Kharth stared at where he’d been. When she blinked, she saw Logan’s seared, mutilated face in front of her eyes.

Airex spoke first, again in that detached tone. ‘I expect he will do something rash.’

Cortez sucked her teeth. ‘We’re not nearly done getting information out of this place. We should finish scans and bail. But…’ Kharth felt them both turn to her as one, and a beat later, Cortez continued. ‘Sae… do you want to…’

‘Return to the ship, Commander.’ Airex’s voice was more firm, and that helped. ‘We’ll wrap up here.’

She stared at nothing for a moment. When she tried to find anything – a feeling, a thought, a desire – there was nothing but the same echoing hum she’d felt when the power core had overloaded.

And when the blue transporter light consumed her to bring her back to Endeavour, she didn’t know if she’d assented, or if they’d just made the decision for her.