At the edges of my vision, everything bends. The light changes colour. It turns silvery and then blue, and then it vibrates. Now the temperature in the carriage plummets and my breath turns to fog and the windows frost over. The next thing I’m aware of is a complete shutdown of noise. It’s as if an invisible dome has clamped down over the carriage, blocking out every sound. Then I feel my body become weightless. And I lift into the air.

I’m floating.

What the hell? I’m floating.

My hair sails up around my face and I see Bea and all the other passengers stone-still in their seats beneath me. It’s as if the Tube has transformed into an interstellar rocket and I’m the only one blasting through space in zero gravity. Which is one hundred percent not possible.

But as I try to get my head around this, I hear it.

A sound like nothing I’ve heard before. A frightening, pain-wrought and drawn-out noise. Not human. Not animal. Something else. Something primeval.

SKRAAAAA­AAAAA­AAAAA­AAAK!

Birdlike and quick, a shadow flashes past the frosted windows. I spin around. Loud screeches fill the air. A stench like a gutted beast.

And I see it now.

And every part of me is afraid.

It crawls through the space from the next carriage along. A humanoid thing. Naked and hairless. Head, torso, arms and a pair of long, sinewy legs leading to clawed feet. A network of dark capillaries fan like roots beneath pink, wrinkled skin. On its back, buckled and bony wings bend to the carriage walls. Eyes, black holes staring from a gaunt, misshapen face. Its mouth, stretched and huge, revealing rows of teeth. It drags itself forward using long hooks on its wings to haul itself along the carriage floor. Along the carriage floor…towards Bea. I try to move—to get to her—but it’s impossible. Bea is between me and the beast and, like me, she’s floating.

This isn’t real. This can’t be happening.

The creature lurches towards Bea.

“NO!” I shout. My voice is hollow, like an echo.

It’s close now. So, so close.

Oh god.

No.

Nononono.

NO!

It’s on her. It leans into her, slavering. Digs its barblike hooks into her.

“Don’t you touch her!” I scream, throat closing.

The creature looks at me with ferocity. It cradles Bea’s limp body in its talons. I get a sense of its hunger, its impatience. I’m feeling light-headed. Dizzy.

“You leave her alone,” I plead, my voice desperate and small. “Please, just…leave her. Take me. Take me instead.”

The world begins to spin. Everything blurs.

Thump!

I slam down on the floor, flat on my stomach. The coffee splatters. The lights glare on and when I raise my head from the ground, the creature is gone.

And so are the other passengers, every single one.