‘Right,’ said Police Sergeant Lightfoot. ‘These ’ere lads from Museum Security will escort you to the wagon outside. From whence I shall take you to the lock-up.’

He glanced down at Xandra, lying on the floor. ‘On your feet, lass. Chop, chop.’

‘She can’t,’ Lex piped up, ready to defend his sister.

‘Can’t … or won’t?’ said Lightfoot.

‘Can’t,’ said Xandra. ‘I have muscular dystrophy.’

‘What the blazes is that?’ demanded Lightfoot.

‘It’s a disease,’ piped up Caruthers. ‘It prevents the lass from walking.’

‘Oh.’ If it was possible for a rhino to look embarrassed, Lightfoot did. ‘Righto, then. Carry ’er.’

He turned and stomped away.

‘Apologies, Miss Volodin,’ said Caruthers, as he and another security croc lifted her up by the arms.

Xandra, not used to being manhandled like this, couldn’t help yelping as they lifted her up. She could feel the roughness of their scales, even through her clothing. She couldn’t quite believe this was happening.

Xandra and the two crocodiles were followed by Lex, who was followed by the other security guards. As they were leaving, Xandra noticed that the cow in the dress was still there, standing by the door, mouth hanging open. As the strange procession went past, the cow stared wide-eyed at Xandra, and began to scream again.

The scream faded as Xandra, Lex and their escort wound their way to the entrance of the Victoria and Albert Museum. The building was extraordinarily beautiful, filled with amazing exhibits ranging from artworks to mechanical contraptions; from taxidermied birds to splayed-out insects on cork boards. But Xandra barely noticed their incredible surroundings, because as they went through the museum they passed one well-dressed animal after another – sheep in tailored suits; cats and dogs in elaborate dresses; cows and bulls in elegant attire – all of them walking around on their hind legs. And as they went along, these animals stopped and stared and gaped, as if Xandra and Lex were the oddities.

Xandra felt like she was an exhibit being paraded about for the amusement of others. Despite the large spacious interior of the museum, it all felt like it was closing in on her. So it was with much relief that she emerged into the sunshine.

Xandra and Lex gasped.

They were in a bustling city – roads, footpaths, buildings, and in the distance, a flag fluttering on the roof of a palace. But the streets and vehicles were full of animals.

Lightfoot led them to a vehicle parked outside the museum. It was an enclosed metal wagon with double-doors at the rear. It seemed like it should have a couple of horses at the front to pull it. Instead it had a smaller vehicle, like an engine on wheels. A mass of gears and cogs, it belched steam from a pipe on its top. It was attached to the wagon by a metal strut and two cables ran from the engine to a couple of levers atop the wagon, behind which was a seat.

‘In they go,’ instructed Lightfoot, as he began to haul himself up into the driver’s seat.

Xandra was carried into the back of the wagon and gently placed onto one of the two wooden bench seats. Lex followed and sat next to her. The doors were closed and the wagon took off with a lurch.

Twisting around in her seat, Xandra was just able to see out of the small, barred window. Lex also peered out.

As they reached the end of the street, they passed a large domed building with a sign:

THE ORATORY SCHOOL FOR CIVILISED ANIMALS. But what came next was even more astounding.

As they moved past the building, they were met by a lush expanse of greenery. The park was bookended by beautiful buildings. And rising up above the trees was an elaborate construction of glass and steel. It towered over the park and glinted in the sunshine, like an enormous jewel. The palatial building was at least a third of the size of the park. Temporary fencing had been erected around the gardens to keep onlookers at bay.

Xandra’s eyes locked onto the structure and a yearning she couldn’t explain stirred within her. She felt a strange tugging – a need to visit the glass building; to go inside. It was like the weird feeling she’d had about the Doorway painting.

‘I want to go there,’ said Xandra.

‘What?’ asked Lex.

‘I need to go there,’ said Xandra. ‘It’s … it’s beautiful and amazing and … and … there’s something special … and …’

‘What are you talking about?’ asked Lex.

Xandra continued to gaze at the building, lost in her thoughts. As the wagon turned into another street, the view of the park and its glass jewel was gone. Xandra sighed, the yearning replaced by an unexplainable ache.

‘Are you okay?’ asked Lex.

‘What?’ Xandra turned to her brother. ‘Um … yeah. I’m okay.’

‘You sure?’

Xandra nodded. But she wasn’t all right. She’d been so amazed and excited by the sights … but now it hit her. This was some strange other world, and they had no way of getting home. She could feel the fear building inside her. What would happen to them? They had already been arrested. What next?

Xandra regarded her brother, and saw her own concerns mirrored in his eyes. She couldn’t let her fear win. She had to keep control.

‘We need to work out where we are,’ Xandra whispered.

‘That’s what I’ve been trying to do,’ said Lex. ‘And about the only thing I can think of is that we’ve gone through a tear in the fabric of time and space.’

‘Lex!’ Xandra looked sternly at her brother. ‘This isn’t Doctor Who. This is really happening.’

‘Yeah, well … if you’ve got a better explanation, I’m listening.’ He folded his arms across his chest with an I-know-better-than-you attitude.

Xandra didn’t have a better explanation. How could she?

The wagon lurched and stopped. Through the window Xandra saw an imposing, grey stone building. They heard Lightfoot jumping down from the driver’s seat and a moment later, the doors swung open.

‘Out you come, lad,’ said the police sergeant. Then he turned and shouted: ‘We need two constables over here, chop, chop.’

Lex hopped out of the wagon and two more police rhinos appeared. They stopped and gaped.

‘What in blazes is –’ the first rhino began.

‘Mind your manners, lads,’ warned Lightfoot. ‘The young lady is unable to walk. Please assist her.’

They lifted Xandra out and carried her up the steps towards the building entrance. Lex followed.

The sign above the doors read:

LONDINIUM POLICE.

‘Londinium,’ Xandra said to herself. ‘Sounds Latin.’

‘Straight to the lock-up,’ instructed Lightfoot.

Xandra and Lex were taken past the reception counter where a sheep in a three-piece suit was arguing with another police rhino. In the area behind the counter, police rhinos looked up in surprise from their oversized desks.

At the end of the room, a door led to a long corridor with cells on either side. Xandra stared as they passed an array of dishevelled and poorly dressed animals behind bars. Reaching the end of the corridor, Lightfoot unlocked the door of the final cell and stood back as Xandra was placed on the bottom level of a bunk bed. Lex sat down beside her.

The constables left, leaving Lightfoot standing by the door, eyes trained on the twins. He sucked at his teeth noisily.

‘What’s going to happen to us?’ asked Xandra.

‘I don’t rightly know,’ admitted Lightfoot. ‘For starters, I need to report all this to the superintendent. He’ll know what to do … I hope.’

Stepping out of the cell, Lightfoot clanged the door shut and locked it. As he left, Xandra and Lex saw that all the animals in the other cells were staring at them. Xandra shivered, a cold fear gripping her insides.

‘I’m scared,’ said Lex.

She nodded. ‘Me too.’