We said goodbye to Agnes in front of her cottage, as she set out for her nightly vigil by the loch, and piled into the Jeep to visit Dr. Sidris. We drove over the bridge through the middle of the village, and around to the north side of Loch Tay, where the road was higher than the south bank. I squinted my eyes, trying to see Agnes, but she was too far away to be anything more than a large dot. We’d only been in each other’s company for a few hours but I felt a kinship with her, because of our similar experiences, and was sad leaving her behind.

The round wound its way through dense woodland and we bounced through deep potholes in the road, Dr. Pendle letting out a little puff of air with each one. Max shot him a concerned look, and Dr. Pendle said, “I think I ate too many oatcakes. Please just ignore me.”

Max stared ahead at the road, without replying. I closed my eyes, trying to block out the slightly sick sensation building in my stomach because of the bumpy road. I hadn’t confessed my travel sickness to them. In a quiet voice, Max asked, “Why didn’t you tell her the truth?”

I kept my eyes closed, aware that they were talking about something I likely wasn’t supposed to hear. I heard Dr. Pendle sigh, and then say, “I was going to, for a minute, I really was. But I knew she’d ask more questions, and I didn’t want to tell a string of lies. I decided it wouldn’t be helpful for her to hear the whole truth.”

“Even though you’ve taught us that the truth is always the right road to take?”

“Even so. Think of it this way: the sample size of those who have returned from the deep is exactly one. And those who knew her before she disappeared all said that apart from appearance, she had changed completely. There were no traits that had improved during her time in the water – quite the opposite in fact. She terrified everyone around her. I didn’t want to give Agnes false hope. Nor did I want to fill her head with worry about what must be happening in the deep, to change a person so radically.”

After a pause, Max said softly, “I understand. I didn’t mean to be rude in questioning you.”

“Not at all – you’re right to question everything. That’s the way of science, even strange science like ours. I question my own actions – I’m not sure I did the right thing, either. Part of me feels as though Agnes deserves the truth, no matter how difficult it is to hear.”

I realized in that moment that I harboured a deep-seated hope that Rufus would come back from the deep one day. I wanted him to be freed from whatever it was that had stolen him away, but more than that I wanted to see him, to spend time with him again. But I’d never once considered that he would come back as a completely changed man, and one I might be frightened of. The thought was too awful to dwell on, so I tried to force it out of my head.

A few minutes later, the Jeep stopped jerking and bumping along the road, and I opened my eyes to see that we were in a village. Max rolled his window down, and the loud sound of rushing water filled the car.

“One of my favourite sounds in the world,” he said. Looking in the rear-view mirror he said to me, “The famous Falls of Dochart. Welcome to Killin.”

He drove past them slowly, as I gaped out the window. The amber glow from the street-lights was just bright enough to illuminate a white-capped rush of water rushing under the bridge we were about to cross. A minute later, Max pulled the Jeep off the road, in front of a small, white cottage. Through the window, I could see a large fire blazing and a small man sitting in a large armchair beside it, bent over a large book. A collie lay at his feet, asleep.

Dr. Pendle knocked once and then swung the door open, calling out, “Sylvester, we’ve arrived!” The collie bounded up to him. “Oh hello, Davis. I might just have something for you.” He reached into his pocket and pulled out a bone-shaped treat. I wondered how long he’d been carrying it around for.

“Welcome, welcome!” Dr. Sidris said loudly. “Come in and get settled by the fire. I’ll get the kettle on. Or perhaps we should start with whisky? There’s a fair nip in the air tonight.”

“Tea would be grand,” Dr. Pendle said. “And I’ll fix it.”

Dr. Sidris followed him through to the tiny, dark kitchen, with Max and I trailing behind. “I’ve been looking through the texts, trying to solve the riddle you posed when you telephoned me earlier. Something about a mind-shifter rang a distant bell, but I couldn’t remember where or when I’d read about it. Well, I think I’ve found it.”

He was struggling to open a large, round tin, so Max took it from him and pulled the lid off in one swift motion. “You could have at least made it look a bit more difficult than that,” he said, looking at Max with amused irritation. “But thank you. Yes, I think I’ve identified the creature you heard about tonight as a silberflöte.”

“A silberflöte? I can’t say I’ve ever heard of it,” Dr. Pendle said.

“No, well they’re not very common in the literature. Austrian. They’re said to be able to plant thoughts in human minds. Hence, I suppose, the metaphor of the silver flute, impregnating people’s minds.”

“Symbolic of a wand, maybe,” Max said.

Dr. Silbis turned to look at him, eyes twinkling. “Good thinking, yes. One of the sources suggests that the silberflöte is capable of stealing away thoughts and memories, by holding its finger – or the nearest it has to a finger – up against the human’s head. Pulls it right out, and discards it.”

“Mind control,” Dr. Pendle said, his voice thick. “This is new for us.”

“Abduction and shape-shifting have been your bread and butter for so long. And now something different comes along – some marmalade, if you will.” Dr. Silbis cuffed me on the shoulder and said, “One thing you should know about me is that I don’t come at this from the same perspective as Alasdair. I love the beauty of the stories that have been handed down to us over the years, across cultures and places, but I don’t believe that any of it is true.”

The kettle reached its peak of boiling as he said those last words and switched itself off, leaving silence hanging in the air for a long moment, during which time he stared at me. “Oh, I see. You believe in it too, don’t you?”

As I tried to work out how to word an answer, Dr. Pendle stepped in and said, “Please leave Thom alone. He doesn’t need to be in your spotlight right now. He can talk to you about his beliefs once he’s had the chance to get to know you.”

Dr. Silbis continued to stare at me for a minute or so until, finally, he looked away. “Well, yes, quite – we can exchange belief systems another time. Anyway, let me tell you more about what I’ve learned.”

We moved back through to the sitting room, which was so hot it was like sitting inside one of the circles of hell. Clearly, though, Dr. Silbis didn’t think so, because he was wearing a cardigan, and slippers.

“There’s an interesting connection between the lore and what you heard tonight, in that the silberflöte speak to parents. They ask for the parents’ permission to take their child away in some stories. In others, they tell the parents to say their goodbyes, because they’re never going to see their child again.”

“So, what you’re saying is they’re aggressive, perhaps even hostile, but nowhere else have we read about water beasts actually asking for permission, or announcing their intention ahead of time.”

“Precisely,” Dr. Silbis said, taking a large bite out of a shortbread biscuit. “They’re either deliberately cruel, or working to some code of honour, as much as it can be said there is one.”

My own voice surprised me. “Isn’t the important aspect that they tell the parents the fate of their child? I mean, the not knowing is the cruellest part, I would say.”

Everyone looked at me, and I felt my cheeks grow red. “It is significant, I agree,” Dr. Pendle said gently. “Although their actions can be interpreted as cruel, their honesty is commendable.”

“And not everyone would interpret their actions as cruel,” Dr. Silbis said. “Remember the Nordic lore – Norway and Finland in particular – where it was seen as akin to being a chosen one, to be taken to live in the underwater kingdoms.”

Dr. Pendle nodded. “I remember those conversations with our colleagues from Scandinavia. It made perfect sense when you consider families living in extreme poverty, or with rampant childhood illness. Being taken away was tantamount to the child starting a better life somewhere else.”

Rufus’s face flashed in my mind and, along with it, memories of our last summer together. He’d been fighting an inner battle with things he couldn’t get under control, an addiction that was winning. I’d never, not once, thought his disappearance was linked to his addiction, or that being taken to the deep had been anything other than a catastrophe for him. What if, though, his new life was a better one?

The very thought of it was both comforting, and deeply unsettling. “What evidence is there in the lore of the worlds people are taken to live in?” I hadn’t intended to speak, and blushed again.

Dr. Silbis looked at me with amusement. “Good question, and one I myself am fascinated with. You’ll be aware of Atlantis, of course – now used almost to represent any lost civilization. But as originally presented, by Plato, it was no utopia. In recent times, though, in art and film, it’s been portrayed as a soaring underwater city of dreams.”

He sipped his tea, looking at me over the steam that rose from the cup. “And then there is Hildaland on Orkney, the hidden land. Also known as Eynhallow. Its magic is its ability to disappear during all but the summer months, when the Finfolk – its inhabitants – live in the full light of the long days. In winter, they return to their underwater kingdom, Finfolkaheem.”

The Finfolk again. I remembered the illustrations Dr. Pendle had shown in his lecture, of the shape-shifting creatures, hiding their fins to pass themselves off as human. “Because we don’t have first-hand accounts – that is, from anyone who has travelled to the underwater kingdoms and back again – we’re relying on artists’ representations and interpretations. So, we have huge castles, towering buildings, riches and beauty as far as the eye can see.”

“And how are the humans who are stolen supposed to breathe underwater?”

“Another good question,” Dr. Silbis said, reaching for another shortbread. “Unless the beasts that take them make some kind of biological adaptation – through surgery or similar – to give them gills, they would need to employ some kind of magic.”

Unwelcome images flashed in my mind, of medical procedures carried out on Rufus as he was taken into the depths of The Wash. I pictured Saphrine looking on, a smug smile planted on her face. Magic – I hoped it was magic they used, because I couldn’t bear thinking about the possibility of invasive surgery.

Dr. Pendle must have seen the worry etched across my face, because he interrupted. “Sylvester, would you like to watch the video of the interview with Agnes? Your observations would be very welcome.”

“Of course! I’d be happy to.”

“Perhaps before we start I could show Thom to his room. It’s been a very long day. You ready to turn in, Thom?”

As disappointed as I was not to be included in the discussion about Agnes’s interview, I knew what Dr. Pendle was doing, and I was grateful. We walked up the narrow staircase, then along a short hallway to a room at the rear of the house. He switched on the light and said, “These rooms don’t get any heat from the fire so they’re a bit chilly even at this time of the year, but once you’re under the blankets you’ll soon warm up.”

I thanked him, and we said goodnight. I stood looking out of the window for a few minutes, amazed by how many stars were visible in the night sky. I pulled the curtains, and took off my shirt, exposing my skin to the chilly air. As I bent to take off my socks, I heard a noise behind me, and turned to see Dr. Silbis standing in the doorway. There was an odd expression on his face.

“Oh, I am sorry, I came to bring you a towel and an extra blanket, but I should have knocked first. It’s one of the perils of living alone – I forget my manners.” The strange look, of surprise and something else I couldn’t identify, remained on his face. “I couldn’t help noticing the tattoo on your lower back. What does it signify?”

My hand went involuntarily to the spot, and immediately the light tingle started up again. “Oh this? It’s not a tattoo, it’s a birthmark. I can’t see it, so most of the time I forget it’s there.”

“How extraordinary,” Dr. Silbis said, looking at me like I was a piece of a puzzle he’d been looking for, for a very long time.