A little further on she saw another of those floating spiky balloons. She kept on, and it let her approach close enough to see it was more like a fish than a balloon. She’d seen them sometimes in the lake, little brown ones, and one time Tiber had caught one and showed her that if you tickled its white belly it puffed up. This one was just like that, only bigger, and it swam through the air!

It seemed so sad, and its big brown eyes watched her, blinking from time to time. It shook itself like a dog and swished its tail.

She held the pocketwatch out, and knew if she squeezed it and refused to believe in the pufferfish it would disappear. The fish shook again as if to say no, don’t do it. It spun around, then swam in a circle, then headed on further up the passage. It stopped and looked back, blinking and waving its transparent fins like beckoning hands.

What’s the use of being crazy, Doncia wondered, if you can’t take advantage of it? Even if the fish was imaginary, it seemed to know which way to go. She followed. The fish ignored the flakes of yellow falling like snow from the walls.

It passed five doors then stopped before the sixth. Doncia tried it. Locked. She looked at the fish. The fish stared back. She looked up and down the corridor. The fish stared at the door.

‘Look, fish,’ she whispered, ‘the door is locked. We’ll need to find another way.’

The fish floated to the door and bumped, scratching with its spines.

Doncia, exasperated, tried the door again. It was unlocked!

‘How did you do that?’ she asked. The fish blinked.

She opened the door, and inside was a staircase, leading down and leading up. Was it the same one?

‘You wonderful fish!’ she said, and started up, but before she’d gone a few steps, the pufferfish was blocking her way, and shaking no.

‘You want me to go down?’ Doncia didn’t think that much of an idea, and tried to get past the pufferfish, but it kept blocking her, and its spines were sharp! It stared, unblinking.

‘But I need to get back. It’s getting late. I’m lost down here, puffer!’ She held out her pocketwatch; she could just make the fish disappear.

It shook no, even more frantically.

‘All right, I’ll just take a quick look.’ At least now she’d found the stairs, and she could come back to them.

The fish led her down one more floor to the bottom of the stairwell. The door was wedged open, and they went left. The gaslights here were even further apart, and then there were none. It became so dark the glowing of the fish guided her way. For some reason she was entirely unsurprised that the pufferfish glowed like a paper lantern, it just seemed to make sense. They continued, and the passageway became more like a tunnel, and slowly curved to the right so she couldn’t see too far ahead. It was colder than before. She suddenly realised there were side tunnels, and they were passing them. There were also doors here and there. The fish took a turn to the left, and another, then one to the right. They kept turning until Doncia realised there was no way she could find her way back.

The fish stopped at a larger-than-usual closed door. It bumped into the door, and she guessed it would be unlocked. She turned the handle and pushed gently.

It was dark inside until the pufferfish floated in, and even then, it was such a large space she couldn’t see the walls. There was a loud slow ticking, as if an iron stove was cooling, but the air was quite cold.

‘Slow down fish!’ Doncia whispered. It did, and looked back at her, blinking.

Another glowing pufferfish swam a wavering path towards them. The two seemed excited, and spun about for a moment, then the new fish sped away into the dark till it disappeared, and the original glowing fish followed more slowly.

For a moment Doncia wondered what she was doing, following floating pufferfish into a dark cavern deep under the castle. How had everything got so strange so quickly?

The ticking noise was louder now, and Doncia felt a blast of cold. She stopped, frightened.

‘Where are you taking me?’ she asked the fish in a whisper. ‘And why?’

It stopped and blinked, then beckoned again slowly with one fin. Its mouth opened and closed, as if it spoke, but she heard nothing.

Doncia stepped once toward it. It moved again, just a little. She stepped one more time, and it motioned for her to stop, then pointed.

Doncia looked where it indicated. It was a roughly circular hole, about the size of a door, and she could see more pufferfish floating down inside. Just a few were close, and further away were more, and even further were hundreds and hundreds more, strung out like spirals of stars in a clear night, all glowing warm amber. It was like looking down into a clear ocean teaming with pufferfish, or up into a sky with flying paper lanterns.

Doncia felt like she might overbalance and fall in. Just because the fish could fly didn’t mean she could. Her pufferfish guide made a shivering motion like a quake of fear, and waved her back from the edge. Doncia could see the faint glow of the fish reflecting from rough stairs leading down, but they seemed to get awfully steep awfully fast, and were way too big for any creature Doncia knew, certainly too big for any that might fit through the hole. She took a step back, and another. The hole was quickly invisible. After the initial wonder of it, she was now sure it was something she’d rather not believe in, and was gripping her pocketwatch so hard it was slippery with sweat.

But she couldn’t will it away yet, not until the fish helped her find the way out.

‘Now you’ve shown me this, fish, is it enough? Will you take me back?’

The fish nodded and led the way.