Then something hits the glass. A flat, flippery something that slaps the window right in front of us with such force that it shatters. We fall back, shards of glass and window frame raining down all around us. I feel points of pain on my hands and face as the pieces cut in.

Then something huge is there, slipping through the shattered window – a fast-moving shadow that blots out the moonlight above. It moves fast, jumping over our heads, hitting the rampart wall with a clatter. It begins to throw itself over the edge.

Except it can’t.

Violet is jerked to her feet by some tremendous force. I see that she is going hands first, and I realize why: she is holding on to something!

Is it a tentacle? Or a tail? Or just a piece of hosepipe? In the gloom, there is no way I can tell. All I can see is that if Violet doesn’t let go, she’ll be pulled over the ramparts too, down onto the tooth-like steeples of Maw Rocks, far below.

So I grab her by the boot and am dragged hard against the wall.

Let go! I want to shout, but I can’t. Not with the air being crushed out of my lungs. I struggle up, seize her coat with my other hand and pull back as hard as I can. From here, I look down the wall. Violet is now halfway over the rampart, her hair dangling crazily over her face, her fists still tightly balled as she clings on to … whatever it is!

The two orbs of light flash again. There’s a shrieking howl, and something swipes across my field of vision. Is it a hand? Is it a claw or a flipper?

Violet cries out in pain and finally lets go, and we both fall back onto the steps. The dark shape of what could be a tail whips away, and I jump up to the wall, desperate to get a good look at whatever it is attached to.

I expect to hear a thud, and maybe the crunch of breaking bone, as the tail-owner falls and hits the rocks. But instead there’s just a faint, flippery sound, then nothing. A shadow flits between two spurs of rock, vanishing in a swirl of mist. There’s a hint of movement in the fog further down the beach, and then even that is gone. Soon all we can hear is the faint washing of the tide as the invisible sea creeps slowly back up the land.

DR THALASSI

“WHEN I FOUND OUT who you were, Violet Parma, I thought your arrival might mean trouble for this town. But I never thought vandalism would be the problem. Why on earth are you breaking windows in my museum?”