Irene frowned, thinking. ‘What’s the largest reasonably airtight container we have?’

‘Probably one of our suitcases,’ Kai suggested. ‘It’s not totally airtight, but there aren’t any cracks in it big enough for the spiders to get out, if they’re inside.’

‘Right. And the suitcases are in the attic, aren’t they?’

Kai took a deep breath. ‘Stay right here,’ he said and was running for the stairs before she could tell him to stop.

Technically she was rather relieved not to be running through the place, with spiders lurking in corners and ready to jump out at her – or should that be drop down on her? – at the slightest provocation. But she still felt a little guilty that he’d gone off to take the risk. Perhaps she was being overprotective.

She heard his footsteps upstairs, and the thump of the attic trapdoor swinging down from the ceiling, followed by the banging of cases and trunks being shifted round. It was far too easy to imagine huge, heaving cobwebbed nests of giant spiders in the attic. She forced herself to focus on her immediate surroundings – and look, the spider that had been crawling around by the light switch was emerging again and picking its way down the wall. There were other little twitches and barely visible movements coming from the darkest corners of the hall. The light had been so bright and welcome a moment ago. But now it merely threw possible hiding places for spiders into stark relief. And there were far too many of them. Irene was abruptly very grateful that she was in boots and trousers.

‘I’d almost prefer to be back in a burning building with the troops outside,’ she muttered to herself.

‘Sorry?’ Kai came thundering down the stairs, banging the suitcase he was carrying against the balustrade posts in his haste. Irene winced as she saw another twitching clot of shadow drop from under the stair rail and scuttle for cover. ‘Any problems?’

‘Not now,’ she said with relief. She took the case from him and opened it, placing it on the floor in front of them. ‘Get ready to brace me.’

Kai simply nodded.

Irene took a deep breath, filling her lungs, then shouted in the Language, her voice loud enough to be heard throughout their lodgings, ‘Spiders, come here and get into the suitcase on the floor!’

The loose command structure of the sentence, and the fact that she was attempting to exert her will on living beings – if not humans – made her sway at the sudden drain of energy. Kai, with the expertise of both warning and experience, caught her with an arm around her shoulders, and held her upright against him as the shadowy corners of their lodgings came to life.

Spiders as big as the first one came scuttling from the folds of coats hanging in the hat stands, dropping from the upper corners of the ceiling, and levering themselves out from behind the shabby pictures that hung in the hallway. A couple of dozen of them came in a wave down the stairs, heaving and jerking along in a mincing eight-legged gait that was too fast for peace of mind. Irene watched as they clambered into her suitcase, forming a hairy, seething mat across the interior, climbing over each other and waving their legs in the air. A few normal spiders had joined the rush and ran round inside rather pathetically, tiny in comparison to their bigger cousins.

She gave it ten seconds after the last spider had climbed in, then kicked the lid closed and sat firmly on it, snapping the catches shut.

‘We could throw it on a bonfire,’ Kai suggested. ‘No, wait, they might get out when the case burns. Perhaps if we throw it in the Thames?’

‘Kai,’ Irene said firmly. ‘I’m surprised at you. This is a valid route for investigation. We don’t simply want to destroy them – first we want to find out everything we can about them. But before that, I am going through this place with another suitcase. I’ll use the Language to hatch any hidden eggs and make absolutely sure we’ve found them all.’

Kai evidently hadn’t thought about the possibility of eggs. He shuddered and glared down at the suitcase. ‘Disgusting creatures. How do you suppose they got into the house?’

‘We won’t know till we’ve checked,’ Irene said, brushing herself off. ‘Could be a broken window, or a hole in the roof. It could be . . .’ She looked at the front door. ‘Well, it would be incredibly blatant, but you could just about push them through the letterbox, if they cooperated.’

‘At least it’ll interest Vale,’ Kai said with resignation, as they went to find another suitcase.

The all-night pet shop down the road was an upper-class one, gleaming with up-to-date chrome and high-power lamps, and little steam-powered climate systems hissed along the rows of tanks and cages. It was complete with pedigree puppies, Persian kittens, glass tanks full of brightly coloured and probably incompatible fish, and a proprietor who didn’t want to serve them. She was stick-insect thin, with straw-pale hair the same shade as the blond ferret ripping toys apart in a cage behind her, and was dressed in spotless dark blue with heavy leather bracers on her forearms.

‘It’s not that I don’t want to be helpful,’ she protested icily, ‘but I’m afraid I really don’t understand what you could possibly want with a humble establishment like my own, which only serves the most refined of clients.’

‘We have two suitcases full of giant spiders,’ Irene said pleasantly. She’d taken ten minutes to change into proper clothing for this alternate world and get rid of most of the ash, so she knew that she looked like a respectable woman, if not a stinking rich one. ‘We need an expert’s opinion.’