The air in the Cardassian Science Ministry’s conference room was as cold as the discussions had been. Starfleet Command had sent Hargreaves and the Caliburn here to play poker against the best with half a hand, and even his assistance against the scant, probing attacks the Vaadwaur had launched against the Union’s homeworld had given him few favours. The fact he was even granted this meeting was a sign of how far he’d come, and how far he’d had to come.

Hands clasped behind his back, he looked up at the sky, at the bustling dots like ants amidst the clouds he knew were the repair teams on the lower echelons of Cardassia Prime’s orbital defensive infrastructure. A pulse of light streaking nearby – though, in likelihood, thousands of kilometres away – marked the sign of a defence vessel repositioning through the upper atmosphere.

The door hissed open behind him, and Hargreaves turned, shoulders squared. Doctor Jatime Varet entered, the slight woman’s presence filling the room. She held all the cards, and they both knew it. As Director of the Theoretical Subspace Division of the Cardassian Science Ministry, she had been both his primary obstacle and only hope for the past four weeks.

‘Captain.’ The PADD in her hand remained clutched tightly to her chest. ‘I’ve reviewed your latest proposal.’

Hargreaves had learned to read Cardassian body language well enough over the years to know this meeting would be different. A slight forward tilt of her head. The loosening of her shoulders. There was a subtle shift in position. After weeks of refusals, redirections, and bureaucratic stonewalling, something had changed.

‘You’ve made a compelling case for cooperation,’ Varet continued, her voice measured. ‘Though I must note that Federation scientific resources appear inadequate to solve this problem independently.’

Hargreaves allowed himself a thin smile. Cardassian pride remained intact even now. ‘While the Union’s dispersal of forces cannot implement any solution alone. Neither of us can solve this without the other.’

Varet activated the large display screen on the wall. ‘Three hours ago, we received this transmission from the Pentath system.’

The screen filled with chaotic sensor readings that coalesced into a tactical display showing four Cardassian vessels engaged with what appeared to be twice as many Vaadwaur ships. The battle was brief and brutal. When it ended, the Cardassian ships were in retreat, and Pentath III, a world of nearly two billion Cardassians, was exposed.

‘The Blackout is lifting in sectors where your Starfleet has destroyed the outposts buried in Underspace,’ Varet said softly. ‘We now see more clearly what we face. What we all face.’

She placed her PADD on the conference table and pushed it toward him. ‘The Ministry has authorised me to share our complete technical data on the tetryon pulse platforms we deployed last year. All of it.’

Hargreaves picked it up and scanned it quickly. This was everything: field equations, resonance frequencies, construction schematics. All the data that had been denied to him for weeks.

‘Why now?’ he asked, though he knew the answer.

‘Because your theory was correct, Captain.’ Varet moved to stand beside him at the window. ‘Our preliminary analysis confirms it. The tetryon pulse we deployed last year to seal the apertures did not simply close the tunnels. It created a subspace resonance pattern that remains detectable. Dormant, but present.’

‘And if we can reactivate that pattern, strengthen it…’

‘We can create a permanent barrier,’ Maret finished. ‘One that the Vaadwaur cannot bypass. Your Federation science ships mapped Underspace across the quadrant. Your subspace sensor arrays have identified dozens of apertures. Combined with our tetryon technology…’

‘We can build a wall,’ Hargreaves said. ‘Not just close individual apertures, but fundamentally alter the subspace topology of the entire Underspace network in the Alpha and Beta Quadrants.’

Varet’s expression remained neutral, but he saw the glint in her eye. It wasn’t hope in the face of despair. It was a scientist relishing a new challenge. ‘My government has authorised the construction of a new tetryon pulse platform at the aperture near Cardassia Prime. It will serve as the focal point for the network-wide cascade.’

‘The Caliburn can aid in the construction,’ Hargreaves offered immediately.

‘That would be… acceptable. We estimate two weeks to complete the primary platform and synchronise it with the remnants of our remaining network.’

Hargreaves moved to the tactical display and called up a map of known Underspace apertures. ‘With luck, more Blackout Outposts will be neutralised by then. Communications will improve. We can coordinate the final pulse across multiple entry points. If we share this information with ships we can contact, in key positions, able to build platforms…’

‘We can create redundancies,’ Varet agreed.

For a moment, both officers stood in silence, contemplating the display. Dozens of points of light represented apertures scattered across two quadrants, points of vulnerability that had allowed an enemy from across the galaxy to strike at the heart of their civilisations.

‘I must ask, Captain,’ Varet said finally. ‘What assurances do we have that Starfleet won’t use this technology against Cardassia in the future? Or that you won’t simply disable the Wall once the Vaadwaur are defeated to study Underspace for your own purposes?’

‘The same assurances we have that Cardassia won’t use it against us, Doctor,’ said Hargreaves simply. ‘None, except our mutual understanding that some threats transcend borders. And our recognition that neither of us wishes to face the Vaadwaur again.’

She nodded. ‘It is our hope that as Underspace harmonics fluctuate when we launch the pulse, the Supremacy will realise their best choice is to withdraw. But this Wall does not defeat them. It only stops them from coming back.’

‘The tide is turning,’ Hargreaves said. ‘Blackout Outposts are beginning to fall. Our fleets are able to combine and push the enemy back.’

‘But if we get this wrong, all we do is cut them off. And nothing is more dangerous than a cornered enemy.’

‘I wasn’t sure the Vaadwaur could become more dangerous. But you make a fine point, Doctor. And the only answer is that we must do it right.’

Varet considered this, then extended her hand in the human gesture she must have studied. ‘Then we have an agreement, Captain Hargreaves. The Cardassian Union and the United Federation of Planets will build this wall together.’

Hargreaves clasped her hand firmly. ‘Together.’

In Play:

• This Story sets up one part of the campaign’s resolution, explaining why the Vaadwaur, once defeated, won’t come back.
• You do not have to incorporate The Wall into your mission.
• Across the Federation, the Blackout is beginning to waver as outposts are destroyed. You can choose how, or if, this affects your mission. Perhaps transmissions begin to creep through. Perhaps long-range sensors can work again. Perhaps not!
• If you wish, your unit may receive a briefing package about The Wall (presumably made possible by the fluctuations in the Blackout). The construction of a platform capable of producing a tetryon pulse near an Underspace aperture, ready to deploy that pulse when the signal is transmitted from Cardassia Prime (via Underspace), can provide a new objective in the final phase.
• At any point in the next two weeks, you can depict The Wall starting to come down. Its effects will not be instantaneous, but cause massive disruptions to Underspace. Perhaps this is what forces local Vaadwaur invaders to withdraw, not wanting to be left completely cut off?