A breath of ice crawled up Irene’s spine. ‘You used the past tense.’

‘You’re an observant woman, Miss Winters.’ Lady Guantes slid a hand beneath her coat and brought out a small sleek pistol. ‘You may wish to observe this.’

Irene had seen a Fae try to break his word once before, with disastrous results. Lady Guantes was far too savvy to risk the same, so Irene refrained from fleeing for cover. ‘We have a sworn truce,’ she said. And only she would have spotted the catch in her voice.

‘Indeed we do.’ Lady Guantes levelled the pistol instead at her husband’s unconscious body, and fired. It was a neat, precise shot. He jerked, then went still again, and a pool of blood began to spread around him. His breath rattled in his throat, then stopped.

Irene should have reacted – she knew she should be reacting – but sheer astonishment held her frozen. ‘You just killed . . . your husband,’ she said. That was the last thing she’d thought Lady Guantes would ever do. Could ever do.

‘Which means he’s no longer your hostage, you can’t return him to me and our truce is over. Now.’

Her tone didn’t change, but her men took her order for the signal it was. The two at the front ran forward, pulling masks over their faces and glass bottles from their coats. Irene was confused until they smashed them to the ground beside her, releasing a wave of gas. Lady Guantes had moved back and was now pulling on a mask of her own.

Irene couldn’t escape the fumes that came boiling up from the smashed glass, and the vapour moved faster than she could form the Language. Her whole body shook from coughing so violently that she couldn’t speak, and tears streamed from her burning eyes, blinding her. Her skin itched where the gas had touched it – hands, face, neck – and her nose was running as if she’d been hit by pneumonia and hay fever together.

Half her mind was raging at her for getting so close to an enemy who she knew was trying to kill her. The more practical part was focused on survival. She still had a gun in her hand. And as Lady Guantes had confirmed, the truce was over.

Irene raised her weapon as she backed away, and fired. She couldn’t see where she was shooting, but Lady Guantes had been in front of her. She heard at least one shot ricochet off stone – but maybe the others hit something. She tried to remember how many bullets the gun held, and wished there were more.

‘Men – move to phase two,’ Lady Guantes said, her voice annoyingly calm.

Damn. I didn’t hit her.

‘Madam!’ That was one of her men. ‘Incoming, outside, police!’

The pause that followed was brief, yet Irene could almost hear Lady Guantes mentally cursing. ‘Cancel that,’ Lady Guantes said. ‘Retreat. Begin diversion protocol. Goodbye, Miss Winters – you won’t enjoy it when I see you again.’

Wood crashed to the floor. Irene still couldn’t open her eyes, or manage coherent words. She tried to analyse the noises. Feet retreating. Noises from the street, briefly, the outer door slamming shut, then nothing. Followed by a sort of slithering, scraping sound.

She retreated, hoping that she was going in the right direction. Her back bumped against the reception desk, and if she had the breath, she would have sighed in relief.

It sounded as if Lady Guantes’ party had left by the main door. But if so, what was making those noises? Her eyes were still streaming too much for her to see, and she felt trapped and helpless. Maybe the police would get here in time. Or maybe not.

‘Irene?’ Catherine sounded very unhappy, and Irene could sympathize with that. ‘Irene, we have a problem.’

Irene tried to speak, but it only set off more coughing.

‘They’re moving!’ Catherine’s hand closed on Irene’s shoulder, and Irene hoped she’d had the sense to cover her face against the gas. ‘Lord Guantes’ men – the ones you’d disabled – are getting up. Do something!’

Irene managed to get out the word, ‘Water . . .’ in between coughs. This wasn’t good. She’d just identified that particular slithering, scraping noise. Those cerebral controller things in the submarine base had made precisely that sound when scrabbling across the floor. And thanks to Irene’s earlier use of the Language, there were a dozen or so unconscious host bodies lying around. She and Catherine would never reach the door to the street in time.

‘Here.’ Catherine caught Irene’s hand and guided it to what felt like the handle of a jug. ‘I think it’s for watering the plants.’

Irene upended the jug over her face, letting water sluice over her until it was empty. She didn’t bother drinking any – it would only aggravate the coughing that still wracked her body.

When it was done, she could finally see again. Lord Guantes’ minions were moving like puppets, first sluggish and hesitant – then jerking into uncoordinated bursts of speed. During these phases, their arms began flailing, their heads whipping round in what seemed to be attempts to orientate themselves. A few unattached mechanical serpents crawled round the wreckage of a wooden crate, seeking convenient hosts.

Irene was still coughing, her throat raw, and she felt sick; she’d never be able to choke out a sentence in the Language. She rounded the end of the reception desk and ducked down, joining Catherine. There had to be writing implements here – ah yes, just there, fountain pen and ink. That would work. She caught Catherine by the arm and pointed at one of the chairs, gesturing for the Fae to get up onto it.

Catherine looked confused but followed Irene’s directions. Her eyes widened as she looked over at the men. ‘They’re coming towards us,’ she said very quietly.

Irene dragged a heavy ledger off the desk, letting it crash to the floor, then knelt on it. With a huge effort she steadied herself; her nose still streamed and her upper body trembled, but her hands were deft enough for the task. She unscrewed the ink bottle and dipped in her finger, then scrawled on the white marble floor in the Language: Floor, hold everything that touches you.

She barely managed to finish the final word and yank her finger back before coughing overcame her again. Then she looked up, her head aching with the after-effects of using the Language.

It had worked. The men swayed where they stood, trying to approach them and failing, then trying again. They were unable to understand why they couldn’t move forward, their eyes blank and mindless. The marble floor had swallowed their feet to the ankle and held them in a grip of stone. The mechanical serpents had been completely sucked under and now formed lines of silver, barely visible through the white stone, like veins of precious metal.

For the moment, their attackers were prisoners. However, enough wriggling – or even enough brute-force yanking with no concern for human bones or tendons – might be enough to get a foot free . . .

Catherine grabbed her hand. ‘Let’s get out of here – now!’

Irene decided that, if Catherine ever had an appraisal, this would merit bonus points. She’d grasped the basic principle of when to evacuate the scene – or more precisely, when to run for it.

The two of them circled the room towards the door, giving the trapped men and mechanical serpents a wide berth. Irene almost expected an ambush when she tugged open the door, but there was nothing unusual outside. No explosions, no kidnappers – nothing but a normal London street. And, wonder of wonders, a couple of police vans turning the corner. Now where were you ten minutes ago? Irene thought ungratefully.