I skulk through the house, listening at doors for signs of movement.

Lundkvist snores, so it's easy to tell that he's still alive, but the girls are quieter, and I really don't want to be the kind of bodyguard that batters down their door.

Eventually – after what seems like centuries – I hear the floorboards creaking under Thalia's feet on her way to the bathroom, and I breathe out. We've made it through another night.

I check the east side of the mountain, but I can only see a few feet down before the cloudbanks swaddle everything. It looks like I could jump down onto them and have a feather-soft landing. For a moment, I'm quite tempted. Softness of any kind has not been part of my life for a while.

The edge of this cliff always whispers to me, especially when I can see the maelstrom at the bottom. Its dark swirls are hypnotic. Sometimes a hole opens up like an eye in the middle of the current, and you can see water pouring in on all sides. Talk about the abyss gazing into you.

I blink and drag myself away from the edge. It's not true that softness plays no part in my life, anyway. There's Clio, even if I only get to look at her.

I spend the next hour chopping wood for her entertainment. It soothes my aches and slows my heartbeat – except when I catch her eye and watch her smile at me. Oh god, I want her.

But wanting her is part of the morning routine too. It reminds me that I'm still alive.

When Thalia calls her away from the window to make breakfast, I decide to check on One-Eye. There's no point using the walkie-talkie – all he does is answer my questions with questions and find fault with my radio-slang. I think technology nettles him.

He's at his post on the ridge overlooking the road, crows perched on either side of him like co-conspirators. They don't take off when I approach, but a couple of them shuffle up to make room for me.

One-Eye has shoulder-length grey hair and a tanned, weather-beaten face. I think he's Norwegian – that's certainly the language we fall into when we're talking together – but his answers are so curt and monosyllabic that I suspect his real mother tongue is Silence.

There's also the eye-patch, of course. One-Eye's not just a clever name. His remaining eye is a kind of turquoise-blue, like clear, tropical waters where you can see right down to the sands. There's nothing else like it on the mountain. Even Clio's summer dresses pale by comparison.

"How are you?" he says – which throws me off-balance right away, because he's never asked me that before.

I shrug my shoulders. Chopping wood under Clio's gaze has almost loosened the stiffness, but not quite. I still feel like I've been wired too tight – like my nerves are taut and fraying. Can One-Eye tell?

"I'd feel better if there were more of us up here," I confess.

"Lundkvist won't allow it."

That's One-Eye all over. Curt and to the point. He could say other things – that Lundkvist's an idiot, for example, or that he shouldn't be allowed to risk his daughters' lives just because he can't stand soldiers and bodyguards. He only lets me in because I was his translator. He likes to think I'm a scholar – and that just shows what an idiot he is, because I'm certain I'd be a better guard if I was less of a thinker.

I shift my shoulders again, and watch the birds at One-Eye's elbow. One of them has its beak buried in his palm – either pecking at something, or nuzzling him affectionately.

"Do you feed them?" I ask.

"In a manner of speaking."

That's One-Eye all over too. He'll never stoop to straight answers when he can hand out riddles.

The bird hops away, and I watch One-Eye drop his arm. It gives me a weird, vertiginous sense of déjà vu, like some half-remembered dream that's trying to come back to me. There's a word on the tip of my tongue – I can almost taste it – but I have no idea what it is.

I swallow and try to grope my way back to the point. "Do you ever think Lundkvist wants to be attacked?"

One-Eye gives a short, sharp laugh. "What do you expect? He's a Viking. It's a good death. You think he wants to end up in Hel's domain?"

"Whose?"

"Ask your girl Clio."

"She's not my girl!" I protest.

One-Eye's mouth tightens – I think it's supposed to be a smile – and I get the definite sense that this signals the end of our conversation for the day. I'm not really sorry.

I head back to the house. In the kitchen, I find the wreckage which indicates that Clio has been making breakfast. In the centre of the flour-dusted counter, among the dirty pans, is a fresh loaf of ryebread and a bowl of hard-boiled eggs – a proper Scandinavian breakfast.

When I cut the bread and spread it with cod-roe paste, I find that it's amazing – springy and dense, with just the right crunch-to-stodge ratio. It's always like this with Clio. She makes things happen in beautiful, chaotic ways. I suppose you could call her clumsy, but that kind of misses the point. She creates loveliness – it's just that the inevitable by-product of these transformations is a whole lot of mess.

It's magic, that's the word I'm groping for. Not the kind of euphemistic magic people talk about when they're trying to say a girl is charming and sweet. Real magic, as deep as her mother's voice. She soothes the aches out of my shoulders when she's watching me chop wood. She kisses Thalia's scratches and scrapes, and there'll be no trace of them half an hour later. She turns the kitchen into a warzone when she's baking, but she emerges from all that strife with a loaf of bread that tastes like sunshine.

When I've eaten, I pile the plates and pans in the sink, check the east slope of the mountain for the seventh time, and then open the gates to make sure the girls are safe. They like to lie on a blanket outside the compound and watch the clouds.

But when I get there, it's just Clio, luxuriating on a tartan blanket that clashes fiercely with her dress. This is more Clio-chaos. She refuses to blend in or harmonise with her surroundings. It makes guarding her a bit of a challenge, but at least she's fighting back against the all-pervading greyness of this place. I feel like we'd both disappear if she didn't.

"Amazing bread, Clio," I tell her. I don't mention the mess, and she hears me not mentioning the mess, and she smiles in a way that makes me ridiculously happy.

"I'll clean up afterwards," she says, waving a hand.

"After what?"

"After I've investigated these clouds Thalia keeps talking about."

I sit on the blanket and lean back to look at the clouds. I'd like to lie down beside her, but that's an idea that rings alarm bells in my head. I don't want to be inappropriate or unprofessional – I just have no idea how not to be crazy about her.

"What are we looking for, anyway?" I ask, and immediately my brain supplies the words: Bear – Brazil – Horrible Histories actor.

"I don't know exactly," says Clio, squinting up at the sky. "Thalia says she sees the same shapes in the clouds every morning. I told her they were probably trying to give her a message, so she sent me out here to see what kind of a message they give me."

We don't get chubby, fluffy, rounded clouds on this mountain. The winds are too vicious. We get scraps and shreds of cirrus, striping the sky like opalescent banners, before being blow into some other thin, pointy shape. If there's a bear up there, he'd have to be all claws.

"It's called Nephomancy," Clio goes on, an edge of wistfulness to her voice. "Divining the future by interpreting the shapes of clouds. Goes back at least as far as the Ancient Greeks, maybe even the Babylonians. At Stockholm, you could take a whole module on it. Dad said it was the most useless thing he'd ever heard of, and yet here I am, using it."

I shift awkwardly. "Do you miss the University? I mean, it can't be very challenging for you up here."

"It's challenging in a whole different way," she counters. "Anyway, I haven't had a chance to miss my friends. That's the great thing about all dad's remote meetings and press conferences – the wi-fi up here is fantastic. I was on a Zoom-call last night with five study buddies."

"Was one of them your boyfriend?" I mutter.

I'm flinching before the words have even left my mouth, but she doesn't raise her eyebrows, or nudge me, or pin me with her knowing look. She just screws up her face, as if she's contemplating something very unpleasant. "Ugh, no. I put men off. Last boyfriend I had said I was 'too much'."

"What?" I'm half-surprised and half-indignant. "What the hell does that mean?"

She shrugs. "I don't know, I stopped listening. Too loud? Too giggly? Too messy? Who cares?"

"I'm glad you don't care," I say, aware that I'm not really coming off as an indifferent observer here. "It sounds like complete crap to me."

She rolls onto her elbows and starts picking at the grass beyond the blanket. "I get that a lot. I don't know if it's just my personality or... something else. I mean, don't get me wrong, Sweden is my home – I'm Swedish. And most Swedish people are laid-back and lovely, it's just... they tend to like their space. They don't like someone's personality to fill a whole room – unless that person is a man, and the room is a barroom."

"Hah," I say, staring miserably at the blanket between us. "I've been to a few of those gatherings."

She squints sidelong at me. "But you weren't the man in question."

"How can you tell?"

"I can just tell. Anyway, you're too English."

I don't ask for more details. I'm pretty sure I'd find them insulting. In fact, I'm half-Swedish and half-French – I just grew up in England. But I feel like 'English' is international shorthand for 'repressed and dull', and I can't really argue with that.

I shift my shoulders. "You're not too much," I mumble. "You're... just enough."

That didn't come out right, but she still smiles and gives me her usual look – the one that feels like it's nailing my soul to the wall. "Depends on your appetite, I suppose."

I splutter and burst out laughing. It probably reinforces her idea of my Englishness, but I can't help it. She's always doing this to me. I'm ten years older than her, I've been trained in grievous bodily harm, and I can swear in five different languages – yet she has me blushing like a schoolboy.

I want to say more. I want to say, 'Never let anyone tell you you're too much – least of all mean-spirited men with no appetite.' But it sounds so inappropriate, even in my head. Ninety per cent of my conversations with Clio consist of me not saying things.

I look down at the blanket and try to think of something non-controversial to say. "Do you ever wish your dad had a different job? Or – you know – wasn't so good at pissing people off?"

"Hell no!" she says, looking up at me in surprise. "I'm proud of what he does. Aren't you?"

I hunch my shoulders, feeling the rebuke. I'm not contesting the fact that the people he's provoking ought to be provoked. White supremacists, especially in high government office, should be outed and shamed before they can do too much damage, but—

"But it puts you and Thalia at risk," I point out.

"What, from the people who hate us just for existing? We were always at risk from them."

"Yes," I say, squirming a little, "But, before Lundkvist, you were just one of many targets. Now you're right at the top of the call-sheet..."

She laughs at my terminology – maybe also at my squirming tone – but not angrily. She reaches out and touches my hand. "Jason," she says, making an effort with the hard 'J'. In her accent, it sounds like someone chiselling shards off a block of flint, but I can't tell if it's the wrongness or the sudden touch of her hand that makes me shiver. "My life isn't worth more than the lives of those other people on the call-sheet."

I want to argue. I want to say, 'It is to me!' But I can't. Quite apart from the fact that it would be unethical, unprofessional, and all the others 'uns' that echo through my head when I'm talking to Clio, it sounds completely stupid.

Anyway, she's right. It's just that I haven't got to know the other people on the call-sheet. They haven't made me splutter. They haven't soothed the aches in my shoulders just by looking at me. They can't bake a loaf of bread that tastes like sunshine.

I lie down on the blanket, giving up. She hasn't let go of my hand, and I'm sure I'm sweating underneath her grip, but staying silent is the only concealment I'm capable of at the moment.

"So..." I say, breathing out. "Are you getting any messages from these clouds?"

From my perspective, they look like grey-white splinters – as if her voice really was chiselling shards off a block of flint. But as soon as she turns away from me and looks back at the sky, the wind changes. Everything starts moving in another direction. The shards are whipped into a spiral, splintered and torn.

Clio looks back at me. I can see the goosebumps on her arms. It's one of those moments where you notice tiny details, and I think unaccountably of blue and white patterned coffee cups.

"Well, I've got one now," she says. "There's a change coming."