His immediate conclusion when he awoke once more strapped on a gurney was that they were going to resume the torture. A tight strap under his chin held his head immobile, and he could feel bands of pressure where others secured his legs and arms. His mouth felt thick and clammy, familiar evidence that he'd been drugged into submission even as he slept.

He was being wheeled down a passageway, its etched-copper walls alternating with bright strips of light as four blank-eyed Bandati – one at each corner of the gurney – pushed him along, the wheels bumping noisily.

Suddenly, the overhead lights gave way to natural light and open air. A moment later Corso found himself in free-fall, the side of the tower rushing by at enormous speed.

He entered a realm of resounding terror, screaming hoarsely as he plummeted towards the streets and twisting tributaries of the river far below.

The four Bandati were still there, though, each holding one corner of the gurney, but with their wings spread wide to catch the air. Their descent slowed suddenly, the light now picking out the iridescent patterns on their extended wings.

They glided downwards at an eye-wateringly steep angle, the wind whipping the breath from Corso's lungs, before making a sudden and far from gentle landing on what appeared to be a rooftop. They were near the centre of a cluster of buildings standing inside a funnel-shaped space that lay at the tower's heart.

The back of Corso's skull had banged against the gurney several times, almost knocking him unconscious. He felt a warm trickling sensation across his thighs and realized belatedly he'd pissed himself during their sudden descent.

They wheeled him through a wide arch, and into what he soon realized was an elevator big enough to accommodate a hundred humans. The elevator dropped for what felt like a remarkably long time before emerging into what was clearly a subway system, with long, arrow-nosed, windowless trains floating above rails in a well-lit tunnel that vanished into infinity.

There were more Bandati here, most of them armed with weapons slung over heavy grey harnesses. Two of these stepped forward, took charge of the gurney and wheeled it inside one of the trains.

Corso found Honeydew – recognizable by his now-familiar wing-patterning – waiting for him inside. The car they were in jerked slightly and they started to accelerate, the movement so gentle that Corso had only the barest sense they were even under way. Curling patterns, like those that patterned his cell, began to glow across the walls of the car.

'You should know, Mr Corso, that if not for my direct intervention you might be dead by now.' The synthesized voice echoed stiffly. 'I, however, have maintained a stand that you can still be of use to us.'

It took a moment for Corso to realize his restraints had been loosened. He swung his legs slowly to the floor.

'If this is about what happened with Dakota-'

'You failed, Mr Corso.'

Corso laughed, fresh anger blooming deep within his chest. 'You tortured her continuously, and you think she's just going to turn around and help you on my say-so?' He shook his head. 'She's just looking for a fast way to kill herself – has been, ever since Redstone. All you're doing is making it easy for her. The more you punish her, the more she thinks she deserves it.'

He stood up carefully, determined to stand his ground. 'You'll never get her to cooperate, and as long as she's still alive and she can communicate with the derelict, you're never going to get inside it. At least, not without my help.'

'Dakota Merrick is no longer your concern.'

'What?' Corso balled his fists at his sides and stepped closer to the alien. 'What does that mean?'

'It means nothing, Mr Corso. You've proven adequately that you can help us penetrate the derelict's interior, but there have been… setbacks.'

'I already told you, I can't help you as much as I might if I had access to the records on board the Piri Reis.'

'That can be arranged. We want you to retrieve your protocols from the Piri Reis 's stacks.'

At last. 'That still doesn't answer the question of just why in hell I should,' Corso replied carefully. 'You haven't followed through on any of your promises – in fact, apart from trying to pry my brain apart or torture me, this is the first goddamn time I've been out of that tower-cell since we got here! Every step of the way you've treated the pair of us like animals. There's been no sign or evidence of any negotiation. I've been given no opportunity to contact the Freehold, to-'

'You will have your negotiations, Mr Corso.'

'Like hell I will!' he exploded. 'I'm sick and tired of being led on. Bring me a representative of the Freehold, and then maybe we can talk. Until then, go fuck yourself!'

The alien cocked his head to one side slightly, the upper tips of his wings brushing against the ceiling of the subway car. 'You should know that we've had some concern over the political stability of your home world. Are you aware there was a coup there while you were away in the Nova Arctis system?'

'I knew about that.' Corso stared at the alien. 'What about it?'

'The Freehold have become weakened through their infighting, and the Uchidans have been taking advantage of the situation by consolidating recent territorial gains. It's possible civil war may break out again, further weakening your society. In that case, negotiating with them directly is unlikely to prove either fruitful or profitable.'

'How do I know any of this is even true?' Corso retorted.

'Please understand that there is much that has been kept from you, by necessity,' Honeydew continued. 'For this I apologize, but we must have the complete protocols from the Piri Reis. The reason why will become clearer once we reach our final destination.'

Final destination?

'I don't do anything until you bring me a representative of the Freehold Senate,' Corso replied, stabbing one finger at the floor between them. He'd meant it to look commanding, but standing there naked talking to an oversized bat only made him feel ridiculous. 'You have to let me get in contact with my people first.'

'That isn't yet possible.'

Corso shrugged, and folded his arms defiantly. 'Well, then-'

'I have been ordered to kill you if it proves impossible to gain your cooperation.'

Corso blinked. 'What?'

'You are a security risk, a constant problem for my people to deal with during our investigations. In certain respects your expertise is invaluable – but if you withhold that expertise, there's no reason to keep you alive.'

'Wait a minute, I-'

The world turned white, and suddenly Corso was looking up at Honeydew from where he now lay curled up on the floor next to the gurney, pain radiating through his nervous system like hot lava. He saw Honeydew was holding a pain-inductor in the small black palm of his hand.

'Please understand,' Honeydew informed him, 'that your cooperation is vastly preferred. But there are other, less pleasant ways of getting to the information stored in your head.'

Corso tasted blood and realized he'd bitten his tongue. 'I don't know what you mean,' he coughed. Then he tried to stand, but his muscles seemed to have turned to putty.

'We have data-retrieval methods for securing your memories,' Honeydew explained, 'neural maps that can guide us to the information storage areas of your cerebrum. Extracting the information would require highly invasive surgical procedures, and the chances of your surviving such procedures, let alone regaining your current level of cognition, are extremely low.'

'Shit.' Corso laughed weakly. He tried to pull himself up by gripping one leg of the gurney, but it rolled away from him as soon as he put his weight on it and he slid back to the floor. 'You're acting like you don't even need me. Why put me through all this if you don't even need me?'