‘Would it be out of order for me to say that I don’t like this alternate?’ Kai asked. He unbuttoned his coat and reached inside, pulling out the book they’d been sent to fetch, and offered it to Irene.

She took it, conscious of its warmth from the heat of his body. ‘Not at all. I don’t like it either.’

‘So how long before you stop getting . . .’

He was looking for a non-aggressive way of putting it, but Irene was irritated enough about the situation herself, so she felt no need to sugar-coat it. ‘Before I stop getting all the crap jobs, yes? God only knows. I’m on probation, after all. There isn’t a fixed time on that.’

And then she felt guilty at the way Kai’s eyes flicked away from her, and at the flush on his cheeks. After all, her probation was his fault, in a roundabout way. She’d abandoned her duties as Librarian-in-Residence in another world at short notice, because she’d gone running off to save him from kidnapping and slavery – she’d also averted a war in the process. Clearly she was lucky to retain her post at all, but these types of missions were the price. It wasn’t fair to remind him about it. And it didn’t help to brood over it herself: the brooding tended to devolve into corrosive anger, or they’ll-all-realize-they-were-wrong-and-apologize fantasizing, neither of which helped.

‘Let’s get moving,’ she said. ‘If the guards check their records, they’ll realize that we were impostors and they could track us here.’

Kai peered into the shadows. ‘I’m not sure there are any undamaged doors on this floor. Do we need an intact door-and-frame to get through to the Library?’

Irene nodded. And he was right – the place had been trashed very thoroughly. She wished she’d seen it while it was still a functioning collection of books, before the Revolution had gutted it. ‘We do. This could be awkward. We’d better try upstairs.’

‘I’ll go first,’ Kai said, reaching the stairs before she could object. ‘I’m heavier than you are, so you should be safe to tread on a stair if it’ll bear my weight.’

This was not the time or place to get into another will-you-stop-being-so-protective argument. Irene let him go first and followed him gingerly up the creaking stairs, treading only where he trod and hanging onto the chipped balustrade in case of sudden falls.

Upstairs, the first floor was almost as ruined as the ground floor, but there was one door off the large central landing that was still hanging loosely on its hinges. Irene breathed a sigh of relief as she saw it. ‘That should do. Give me a moment.’

She focused on her nature as a sworn Librarian, drawing herself upright and taking a deep breath, then stepped forward to lay her hand against the door, pushing it shut. ‘Open to the Library,’ she said in the Language. Its power to reshape reality was a Librarian’s greatest asset. So in a moment they’d be out of this place, back in the interdimensional collection of books they both worked for, ready to deliver one more volume to its huge archives.

What happened next should definitely not have happened. The door and its frame went up in a burst of fire. Irene stood there in stunned disbelief, barely snatching her hand away from the heat, a concussion of power resounding in her head like a car crash. Kai had to grab her shoulders and drag her back, pulling her away from the flames. They burned hot and white, catching on the wood faster than was natural and spreading across the wall.

‘Fire, go out!’ Irene ordered, but it didn’t work. Usually the Language would interact with the world around her like cogs fitting together and moving in unison, but this time the metaphorical teeth on the cogwheel didn’t catch and the Language failed to grip reality. The flames rose even higher, and she flinched back from them.

‘What happened?’ Kai shouted, raising his voice to be heard above the crackle of the fire. ‘Was it booby-trapped?’

Irene gave herself a mental shake and pulled herself together, flinching back from the spreading fire. She’d been expecting to feel the usual drain of power, but what she’d touched had felt more like a live wire – an antithetical surge of power, which had exploded when she’d tried to touch it with her own. Fortunately it didn’t seem to have affected her, just the door that could have been their route back to the Library. ‘I have no idea,’ she shouted back. ‘Quick, we need to find another entrance! And before this whole place goes up!’ She clutched the book to her chest in a death grip: if she dropped it here and it went up in flames, god only knew how long it would take them to find another copy.

They stumbled to the stairs, smoke already coiling towards them and starting to drift through the shutters and outside. Irene led the way up this time, spurred by the rising crackling of the fire. She heard a crunch behind her as one of the stairs gave way under Kai, but he grunted at her to keep on going up, and a moment later his footsteps were behind her again.

Irene staggered out onto the second floor and looked around. It was as much of a wreck as the ground floor. There were no doors, only empty doorways and broken walls. There was more light, but only because of the large holes in the roof, and the floor was stained where the rain had been coming through.

Perhaps you should have used the Language more efficiently and succeeded in putting out the fire on the first floor. Rather than just screaming ‘Fire!’ and panicking and running away, the cold voice of self-judgement at the back of her mind pointed out. Might it have worked if you’d just tried a little harder? And don’t step on those stained bits of floor, the voice remarked waspishly, they’re probably rotting and unsafe.