When she regained consciousness, Friday could hear waves lapping. She hoped she was on a tropical beach, but she reasoned that the bitter cold she was feeling made that possibility improbable. She opened her eyes to check. It was dark. The green light of the aurora borealis still rippled in the sky. But she was somewhere different. In the eerie glow, she could make out several derelict timber buildings. There was even a church. It all looked abandoned – a Nordic version of a ghost town. She wished she could abandon this place. It was spooky. It did not feel safe.

Friday couldn’t move her hands, but they were warm. It took her a moment to realise she was tied back-to-back with Ian. It was bitterly cold in the wind. The men holding them hostage were just standing round. After the frantic robbery of the Seed Vault and dramatic escape across the tundra, it seemed weird that they were now hanging about.

‘Friday, are you awake?’ whispered Ian.

‘No,’ mumbled Friday.

‘Come on, you need to wake up,’ said Ian.

‘No, I don’t,’ grumbled Friday, ‘leave me alone.’

Ian elbowed her in the ribs.

‘Ow!’ said Friday. ‘What did you do that for?’

‘We’re in sub-zero temperatures in the middle of the night in the Arctic Circle,’ said Ian. ‘If you go to sleep, you’ll die.’

That made sense. Friday struggled to focus her thoughts.

‘What is happening?’ asked Friday. ‘Why are they doing this.’

‘I don’t know,’ said Ian.

Friday looked around. Dr Finsberg was standing at the water’s edge, talking to the woman leader. It was hard to tell anyone’s gender when they were wearing snow gear and a ski mask, but Friday could hear the pitch of her voice.

‘Dr Finsberg was in on the heist?’ said Ian

‘I knew he was up to something,’ said Friday. She spoke softly so their captors couldn’t hear over the wind and lapping waves. ‘He was the only person who could have helped Jonas frame Binky. I should have alerted the local police.’

‘But why?’ asked Ian. ‘Why rob the Seed Vault?’

‘Don’t you recognise who he’s talking to?’ asked Friday.

‘No,’ said Ian. ‘Should I?’

‘She’s someone you know from Bilbao,’ said Friday. ‘That is Dr Lopez.’

‘Dr Lopez?’ asked Ian. ‘You don’t mean – the conservationist from the Bilbao?’

‘The great wheelchair athlete herself,’ said Friday. ‘If you listen carefully, you can hear she speaks English with a Basque accent.’

‘What’s she doing here?’ asked Ian.

‘Picking up her stolen property,’ said Friday. ‘We know she’s been smuggling artworks out of Spain through the Port of Barcelona. Apparently, she’s been smuggling them here in Spain’s deposits to the Seed Vault.’

‘That’s crazy,’ said Ian.

‘It’s brilliant,’ said Friday. ‘The seed deposits are sealed in large plastic tubs. They’re waterproof, temperature-controlled and acid-free – perfect for preserving seeds and art. That’s why she was stealing smaller paintings. They were easier to fit in the tubs. And customs officials wouldn’t be allowed to break the seals and look inside. This is a very clever crime.’

‘It’s totally insane,’ said Ian.

‘Let’s see if I’m right,’ said Friday. She raised her voice and called out to the two on the water’s edge. ‘You don’t need to wear a mask. I know who you are, Dr Lopez.’

Their heads whipped around. Dr Finsberg peered at them in the dim light.

‘What’s she doing here?’ he demanded.

‘You told us to kidnap the princess,’ said Dr Lopez. ‘For security.’

‘She’s not the princess!’ exclaimed Dr Finsberg.

Dr Lopez strode closer to get a better look at Friday. She took out her phone and held it up for comparison. ‘This is the picture you sent me. A short, brown-haired girl wearing exactly that coat. It says, “HKH, Prinsesse Ingrid” embroidered on her chest.’

‘But it’s not her,’ said Dr Finsberg. ‘She’s just an annoying brat. She isn’t even Norwegian.’

‘Wow, that’s harsh,’ said Friday.

‘Harsh but fair,’ said Ian.

‘I prefer to think of myself as an undercover body double for the Princess of Norway,’ said Friday.

‘That does have a ring to it,’ agreed Ian.

‘It doesn’t matter now,’ said Dr Lopez. ‘We got away. No one followed us, except for this idiot.’

‘She’s talking about you,’ said Friday.

‘Don’t worry, I realise how idiotic my regard for you is,’ said Ian.

‘Let’s just kill them,’ said the Dr Finsberg.

‘I’m not killing them,’ said Dr Lopez. ‘I’m an art thief, not a murderer. You do it.’

‘I’m a botanical geneticist! I don’t kill people either,’ said Dr Finsberg.

‘Fine,’ said Dr Lopez. ‘We’ll just leave them here. They’ll die of cold before anyone finds them. Same result, without blood on our hands.’

‘You have a very poor understanding of murder laws if you think that’s the way it works,’ said Friday. ‘Death caused in the commission of a crime is automatically classed as murder in many jurisdictions. I’m not sure about Norwegian law, but I’m sure it’s at the very least frowned upon.’

‘They’ve just decided not to kill us,’ said Ian. ‘Please don’t make them change their minds.’

‘We’re too exposed here, standing on the beach,’ said Dr Lopez. ‘If a helicopter came over they’d spot us. You keep watch. We’ll shelter out of sight in that cave.’ She nodded towards a cave at the northern end of the beach.

‘Fine,’ said Dr Finsberg.

Two of the henchmen grabbed Friday and Ian. They all made their way towards the cave. It was hard for Friday and Ian to walk tied back-to-back. They had to shuffle sideways like crabs. The cave smelled pretty dreadful, but the entrance was large enough for them to get in without too much trouble.

As soon as they were inside, it immediately felt warmer. The temperature was still below zero, but being out of the wind made a big difference. And there were eight of them cramped into the small cave, so it began to warm up a bit just from having so many people in a confined space.

‘What are you waiting for?’ asked Friday. ‘A boat? Or a helicopter? The Norwegian military will be able to track your movements wherever you go. Satellites and radar will follow your every move. Did you take the time to think this escape plan through?’

‘Shut up,’ said Dr Lopez.

‘Yes, please shut up,’ said Ian. ‘A critical analysis of their crime planning is not going to improve their mood.’

‘Planning is so important,’ said Friday. She was definitely concussed and starting to get drowsy again in the comparative warmth. ‘So many criminals focus on the crime, but don’t think through the getaway.’

‘Shut up!’ barked Dr Lopez.

‘That’s no way to speak to a princess,’ said Friday.

‘You realise you’re not a princess, right?’ said Ian.

‘Hmm,’ said Friday, starting to nod off.

Friday felt Ian take her hands in his and squeeze them. She was drifting off. Her brain started to notice all the noises around them. The muffled sound of the waves on the beach outside. The wind whipping across the landscape. The rustle of the men’s coats as they shifted to make themselves comfortable. The mewing of a young animal . . .

Friday’s eyes snapped open. Why could she hear an animal? She listened closely. She could hear nothing at first. Then definitely a mewing. Then two distinct animals mewing and a little snuffling.

‘Where is that sound coming from?’ asked Friday.

‘What sound?’ asked Ian.

‘Listen,’ said Friday. ‘It’s very soft, but it’s an animal.’

They both listened.

‘I don’t hear anything,’ said Ian.

The wind was very loud outside, as were the waves lapping at the shore. But then, there it was! There was a soft mewing.

‘It’s coming from beneath us,’ said Ian.

‘Oh no,’ said Friday.

‘What?’ said Ian.

‘This isn’t a cave,’ said Friday. ‘It’s a den.’

‘What?’ said Ian.

‘Polar bears build dens into snow drifts,’ said Friday. ‘When they go out to hunt, they leave their cubs in a smaller den underneath the floor of the main den.’

‘So you’re saying . . .’ began Ian.

‘We have taken shelter in a polar bear’s home!’ said Friday. ‘And we are sitting on her children.’

The men all just stared at Friday. They couldn’t believe what she was saying.

‘These are lies to unnerve us,’ declared Dr Lopez.

‘Oh, come on,’ said Friday. ‘Think about it. Is it normal for snowdrifts to smell this bad?’

‘They’re from Spain,’ said Ian. ‘They probably don’t experience a lot of snow.’

‘It’s frozen water from the sky,’ said Friday. ‘You don’t have to experience it to know it shouldn’t be bear-scented.’

Just then, there was a low throaty noise.

‘What was that?’ asked Ian.

‘The wind,’ said Dr Lopez.

‘Mumma bear,’ said Friday.

There was another guttural noise from the entrance of the cave.

‘We’re trapped,’ said Ian.

The men started panicking and swearing in Spanish.

‘Can you get us out of these wrist ties?’ Friday asked Ian. He was a master at getting out of handcuffs, so she assumed he’d be good at zip ties too.

Ian didn’t even respond. She suddenly felt her wrists released.

‘There’ll be a ventilation shaft,’ said Friday as she desperately felt about the ceiling of the cave.

‘Just shoot it, just shoot it,’ Dr Lopez was yelling.

‘Don’t shoot the bear!’ said Friday. ‘You’ll only make it angrier!’

One of the men ignored her. He took aim and pulled the trigger. But nothing happened. The hammer clicked, but the gun didn’t fire.

‘The lubricant on your weapon will have frozen,’ said Friday. ‘It’s jammed. It won’t be able to work until you warm it up. Found it!’

Friday started chipping off snow from the roof.

‘Hey!’ said Ian. ‘You’ll bury us alive.’

‘The snow isn’t that deep,’ said Friday. ‘You don’t want to be bear breakfast, do you?’

A big clump of snow fell on Ian’s head, but when he brushed it off, he could see the stars overhead.

‘I can’t believe you’re right about something so weird,’ said Ian.

Friday was struggling to climb out. Ian cupped his hands to give her a leg up.

‘I don’t know why you’re surprised,’ said Friday. ‘I’m almost always right.’

‘Except when you’re spectacularly wrong,’ said Ian, as he followed her out of the hole. Friday was already running towards the beach.

‘Where are you going?’ yelled Ian.

‘To the snowmobiles,’ Friday called back.

The polar bear had chased two of the henchmen over to the abandoned church, where they climbed up on the roof to get away. The bear pounded on the side of the building a few times, then went back to check on her cubs, satisfied that the intruders were no longer a danger.

Dr Lopez and the other three henchmen sprinted across the beach towards the water where Dr Finsberg was waiting.

‘Surely they’re not going to swim?’ asked Friday. ‘They’ll be dead in minutes from hypothermia.’

‘Look,’ said Ian.

Friday’s eyesight wasn’t as good as Ian’s, but after a moment she could see what he was pointing out. Something was emerging from the water. Her first thought was of Poseidon, God of the Sea, rising from the deep. But that seemed unlikely. She soon realised what it was.

‘A submarine!’ said Friday.

‘No wonder they weren’t worried about being tracked by satellites,’ said Ian.

The men started pushing an inflatable boat, loaded with the storage bin from the Seed Vault, into the waves.

The hatch on top of the submarine flipped open. Two sailors emerged. One of them called out to the beach. ‘Dobryy vecher. Izvini my opozdali.’

Dr Lopez called back, ‘My dolzhny speshit.’

‘Are they speaking Russian?’ asked Ian.

‘Okay, I stand corrected,’ said Friday. ‘They put way more planning into the getaway than I gave them credit for.’

Then, suddenly, bright light flooded the bay!

A deafening siren filled the air.

NEE-NAW, NEE-NAW, NEE-NAW!

The light was blinding. It was hard to see the source.

A booming voice came over a loudspeaker, ‘STOP WHERE YOU ARE! THIS IS THE NORWEGIAN NAVY. PREPARE TO BE BOARDED.’

The men on top of the submarine panicked and rushed to get back in the hatch.

‘Nyet! Nyet!’ cried Dr Lopez. ‘Vy ne mozhete uyti! You can’t leave without us!’

The submarine was starting to submerge, before the sailors could get back inside and while the hatch was still open. As the tower of the submarine dipped below the waves, water flooded inside. The men desperately tried to cling to the top.

Someone inside must have realised the mistake and the submarine started to come back up again. The Norwegian navy vessel drew up alongside, grabbed the two men floating in the water and boarded the submarine.

Dr Finsberg and the henchmen on the beach abandoned Dr Lopez and took off, running back to the snowmobiles.

‘The paintings!’ Dr Lopez called after them. ‘Come back and get the paintings!’

‘Leave them! We can rob another art gallery,’ Dr Finsberg called back. ‘But not if we get arrested.’

‘No!’ cried Dr Lopez.

The inflatable boat had started floating on its own, further into the bay. She evidently could not bear to see them float away. Dr Lopez splashed into the water, wading out through the waves towards the boat.

‘We’ve got to stop her!’ said Friday as she took off running. It wasn’t far, but Ian ran much faster. He leapt over the waves and crash-tackled Dr Lopez. They both disappeared under the water, then burst back up again, gasping for breath. Ian had a firm hold of her.

Friday hadn’t even tried to get to Dr Lopez, she was wading towards the inflatable boat.

‘Friday, leave it!’ called Ian. He couldn’t come and help because he was still struggling with Dr Lopez.

Friday kept wading further out. She was short and she was wearing full snow gear, which made progress slow. She was soon chest-deep in water. It was so cold it was painful. The boat was drifting lazily away from the beach. She had to get to it before hypothermia set in. She was starting to feel numb already. The boat was in reach now. She stretched out. Her gloved fingers brushed the side. She couldn’t feel her fingers anymore. She had to go by sight. When her fingers brushed the strap, she grabbed it. Friday was wearing too much clothing to pull herself in, so she turned and started walking back towards the beach, dragging the boat behind her.

It was sluggish work. The extreme cold was making her feel confused and uncoordinated. A deep part of her brain recalled the fact that these were symptoms of stage 2 hypothermia. Everything hurt so much. She willed herself to focus on two things – don’t let go of the strap, and keep walking.

The waves would pick her up and she would lose her footing for a moment, but as soon as her feet touched the rocks again, she kept edging her way forward. The Norwegian navy vessel was still occupied with the submarine. They were not able to help yet. Eventually, Friday pulled the inflatable boat onto the beach and collapsed on the stones.

‘Friday!’ Ian cried. He had tied Dr Lopez to a bollard using her own zip ties. He ran over to help.

‘I’m-m-m c-c-c-cold,’ said Friday. She was shaking so hard her teeth hurt.

Ian grabbed her boots and pulled them off.

‘What are you d-d-d-doing,’ said Friday.

‘You need to warm up,’ said Ian.

He grabbed her snow pants by the ankles and pulled. Friday didn’t protest. She couldn’t feel her legs anyway. She didn’t have the energy to care if he saw them. It was dark and hard to see anyway. Ian took off his own coat and wrapped it around her legs, put his hat on her head and then he lay down on the beach next to her and wrapped her in a big hug, trying to warm her.

‘The navy are here,’ said Ian. ‘They’ll come when they can.’

‘Oh, Ian,’ said Friday, through chattering teeth. ‘Th-thank you for ch-chasing after me.’

‘Across the tundra tonight, or generally in life?’ asked Ian. His face was pressed up against her, trying to share body heat.

‘Both,’ said Friday.

‘It’s okay,’ said Ian. ‘Just think how dull my life would be if I didn’t get into all these life-threatening scrapes with you.’

‘I want d-dull,’ said Friday.

‘No, you don’t,’ said Ian. ‘Nothing about you is ever dull.’

‘Hello, you two!’ said a gruff voice.

Friday blinked several times. There was salt water in her eyes and it was dark, so she was not entirely sure, but it looked like Uncle Bernie was standing over her.

‘Bernie?’ she asked.

‘Yes, it’s me, your uncle,’ said Uncle Bernie.

Friday started to cry. ‘Thank you for identifying yourself. I’m so confused.’

‘I got your message,’ Uncle Bernie said. He had several heavy blankets with him. He knelt down and starting wrapping them around Friday like she was a burrito. ‘Thanks for the tip-off. I guess you were right.’

‘About what?’ asked Ian. Bernie wrapped a blanket around Ian’s shoulders too.

‘The b-boxes,’ said Friday, indicating the storage bin from the Seed Vault. It was still sitting in the inflatable boat.

‘Is that the one?’ asked Bernie.

Friday nodded.

Uncle Bernie lifted the plastic bin out of the boat. Friday struggled to sit up so she could see. Bernie opened the lid. Inside, there were dozens of strange treasures – a vase, a compass, a dagger, a map, an old book . . . Uncle Bernie carefully set each object on the box lid so they could see what was underneath – eight brightly coloured expressionist paintings.

‘The Kandinskys from Bilbao!’ said Ian.

‘Forty million euros’ worth of art,’ said Uncle Bernie. ‘Well done. I never would have found them without you.’