Lachie’s wife, a pleasantly plump woman in her mid-forties, saw them settled, then disappeared into the kitchen while the General and Lachie exchanged what to Cat were a series of meaningless sentences. Sandwiched between Ellie and Henry, she couldn’t think of anything to say that might be of any interest. Luckily, Mrs Lachie bustled out of the kitchen, laden with cake stands. She set them proudly in front of her guests and Cat stared open-mouthed at the array of sweetness. She thought she’d never seen so much butter, flour, sugar and eggs in one place, not even at the Piddle Valley produce show.

‘Amazing, isn’t it,’ Henry said, reaching to pass the scones, pancakes and assorted buns to Cat. ‘And it tastes as good as it looks. When I’m driving back and forth between Northanger and work, I have to take the back roads or I’d be the size of a barrel.’

Mrs Lachie returned with pots of tea and coffee. ‘Don’t be daft, Henry, you’ve got the metabolism of a whippet. Eat up those meringues, now, I made them just for you.’

Cat found it impossible to stop once she’d started. Everything was delicious, but as soon as she’d finished one sweet delight, the General or Mrs Lachie would press another on her. Finally, she knew that if she ate another thing she would be sick. ‘I can’t,’ she moaned, as Mrs Lachie proffered a plate of vanilla slices.

‘I think you’ve done your duty, my dear,’ the General said to Mrs Lachie. ‘Wonderful spread, as ever. Best cakes in the Borders.’

Cat was impressed with the deference that Lachie and his wife showed the General. It was respectful without being servile and she thought it spoke well of her host. Even if he was brusque towards his family sometimes, he was clearly a man who was admired by the world. That couldn’t be the case if he was a vampire, could it? Or if he’d been a brute to his vulnerable wife?

The party moved out to the car park more slowly than they had entered, weighed down by their overindulgence. General Tilney patted his stomach and groaned even though Cat had seen him eat very little. ‘I need more space to stretch out after that,’ he said. ‘Ellie, why don’t you ride with Henry and I’ll take your place. It’s roomier in there.’

Cat felt a pang of dismay. But her friend rode to her rescue. ‘I’d rather ride with you, Father,’ Ellie said quickly. ‘I’ve had so much to eat I’ll get car sick driving with Henry, the way he throws that car round the bends.’

The General harrumphed. ‘You have a point. Very well, if Catherine doesn’t mind Henry’s deplorable driving?’

‘I’ll be fine,’ Cat said cheerfully. ‘My mother says I have an iron constitution.’ Even if it had been a lie, she would have said something similar to secure her place in the car next to Henry. Her only regret was that it would be less than an hour before they arrived at Northanger Abbey.

‘I’ll open the sunroof, make sure there’s plenty of fresh air.’

General Tilney frowned. ‘I don’t think so.’ He looked up at the clouds. ‘We don’t want the noonday sun beating down and giving poor Catherine a headache.’ And so the tinted glass sunroof remained firmly closed.

As soon as they set off, she was reminded of how much more pleasant it was to be Henry’s passenger rather than Johnny’s. He followed sedately in his father’s wake, leaving enough distance between the two cars for her fully to enjoy the rolling hills and fields of sheep and cows they passed through. The landscape was more dramatic than the Piddle Valley, but it was similar enough for her not to feel any sense of unease.

‘It’s really kind of you to come and stay,’ Henry said.

‘Kind? It’s a huge treat for me.’

‘Well, I appreciate Ellie having some decent company for a change. I know you haven’t known each other long, but she counts you as a real friend.’

‘Doesn’t she have other friends at Northanger?’

‘It’s a bit isolated. And because she’s been mostly at boarding school, she never really made friends with the local kids. She’s mostly stuck out there with Father, and when he goes off on one of his mysterious jaunts with the lads – which he does quite a lot – she’s left to her own devices.’

‘Are you not around, then?’

‘Northanger isn’t even half my home these days. I’m an advocate, most weeks I’m in Edinburgh between three and five days.’

Cat raised her eyebrows. ‘You rattle about in that big house in Ainslie Place all by yourself?’

Henry laughed so hard she thought he would steer them into a ditch. ‘God, no. My father takes a house just for the festival. I have a disreputable little flat off the Cowgate, which I rent out during the festival. And that pays my mortgage till Christmas.’

‘It must be hard to go back to that after Ainslie Place and Northanger Abbey.’

‘I’m always sorry to leave Ellie, it’s true.’

‘Not just Ellie, though. Swapping a Borders abbey for a flat, even in Edinburgh, must be hard.’

He grinned. ‘You’ve got high hopes of the abbey, haven’t you?’

‘Of course. Ellie showed me a photo in one of those books of Scottish views. It looks gorgeous. The kind of historic building that ends up starring in a film adaptation of some heart-stopping book about vampires or Jane Austen heroines or ancestral ghosts.’

Henry shook his head. ‘And are you ready for all the horrors that a house like that has to offer? As well as an iron constitution, are you fearless? Are your nerves up to it?’ He dropped his voice to a ghoulish pitch. ‘Can you handle sliding panels, priest holes, secret passageways hidden by ancient tapestries?’

Cat laughed. ‘What, you think I’d be scared so easily? You don’t know me, Henry Tilney. Besides, there’ll be lots of people in the house. It’s not like it’s been standing empty for years and we’re coming back to face down the old ghosts – which is what it would be if this was really a horror movie.’

‘No. We do have electric light nowadays. No more feeling our way down the hall, lit only by the dying embers of a wood fire. And we’ve emerged from that period where we had to sleep on animal skins on the floor in rooms without windows or doors or furniture. But Mrs Danvers, our elderly crone of a housekeeper, does like to keep to the old ways. She insists on making our attractive young female guests sleep in the west wing all alone while the rest of us retire to the east wing with its flush toilets and hot water and wifi.’

‘Mrs Danvers?’ Cat squeaked.

‘Mrs Danvers. She’ll lead you up a different staircase from the rest of us. Down the gloomy passageways. Into an apartment never used since mad Cousin Onesiphorus hung himself from the hammer beams twenty years ago. An apartment lit with one forty-watt bulb barely strong enough to reveal the shadowy tapestries of mythical beasts and deformed grotesques. Will that be all right for you?’

‘I think you’re at the wind-up.’

‘I’ve barely touched on what awaits you at Northanger,’ he said, his tones sepulchral. ‘A broken fiddle, a chest that can’t be opened, a grime-streaked portrait whose eyes follow you round the room. And a dribble of unintelligible hints and malevolent stares from Mrs Danvers. And then she’ll tell you about the vampires and the werewolves and the undead who wander the corridors around your room. She’ll point out that there’s no mobile phone signal anywhere in the abbey and then she’ll leave you, straining to hear the echo of her receding footsteps, convinced you can hear a strange fluttering in the chimney. And then you’ll discover the door has no lock.’

By now Cat was giggling. ‘You’ve been reading too many Hebridean Harpies books. No wonder Ellie doesn’t get many visitors. I don’t believe your housekeeper is called Mrs Danvers either.’

Henry chuckled. ‘You’ll have to wait and see. But don’t shriek when she introduces herself, that really annoys her.’

‘Yeah, right, whatever. So what other delights can I look forward to, alone in the west wing?’

Henry’s voice sank back to its tone of horripilating menace. ‘Nothing more, on the first night. Once you overcome your terror enough to climb into bed, you’ll fall into a restless sleep, broken by vile unsettling nightmares. Nothing more than that. The house will be lulling you into a false sense of security. But on the second, or maybe even the third night, there will be a violent storm.’

‘Of course there will. Peals of thunder that will shake those thick stone walls will bounce off the surrounding hills. Gusts of wind will whistle in the chimney like the screeches of a banshee and ripple through that grotesque tapestry, making it seem to come alive.’

Now Henry was laughing. ‘Are you sure you’ve never been to Northanger before? Never climbed out of bed in the middle of a storm to examine the peculiarities of a tapestry and discovered the secret door that lurks behind it? Never worked your way through a series of logic puzzles and sudokus to open it?’

Cat gave a little scream. ‘Stop it!’

‘And then, once the door falls open, you tiptoe down the wide stone stairs which are lit by an unearthly scarlet light. You hear a crunching underfoot and realise you are trampling dry bones underneath. But something drives you on and you emerge into a vast underground cave where a decadent troupe of vampires are feasting on the body of a white-skinned young woman. Who bears a terrifying resemblance to ...’

‘To who?’ Cat was caught up in it now. Somehow, Henry had plugged into her own strange and secret fantasies.

‘To whom, don’t you mean?’

She gave his arm a gentle punch. ‘To wit, to whom – it doesn’t matter. Who does the victim look like?’

‘Bella Thorpe,’ he intoned, then burst into a cackle of laughter. ‘I can’t keep it up, Cat. You’ll have to make up your own grand finale. But make it smart – as soon as we go round the next bend, we’ll be within sight of Northanger Abbey.’