Prologue

Eleven years ago

LEAVES, MUD AND GRASS DEADEN SOUND. EVEN SCREAMS. The girl knows this. Any sound she might make can’t possibly travel the quarter-mile to the car headlights and streetlamps, to the illuminated windows of tall buildings that she can see beyond the wall. The nearby city isn’t going to help her and screaming will just burn up energy she can’t spare.

She’s alone. A moment ago she wasn’t.

‘Cathy,’ she says. ‘Cathy, this isn’t funny.’

Difficult to imagine anything less funny. So why is someone giggling? Then another sound. A grinding, scraping noise.

She could run. The bridge isn’t far. She might make it.

If she runs, she leaves Cathy behind.

A breeze stirs the leaves of the tree she’s standing beside and she finds she can’t stop shaking. She dressed, a few hours ago, for a hot pub and a heated bus-ride home, not this open space at midnight. Knowing that any second now she may have to run, she lifts first one foot and then the other and takes off her shoes.

‘I’ve had enough now,’ she says, in a voice that doesn’t sound like her own. She steps forward, away from the tree, a little closer to the great slab of rock lying ahead of her on the grass. ‘Cathy,’ she says, ‘where are you?’

Only the scraping answers back.

The stones look taller at night. Not just bigger, but blacker and older. Yet the circle they make seems to have shrunk. She has a sense of those just out of her line of sight slipping closer, playing grandmother’s footsteps; that if she spins round now, there they’ll be, close enough to touch.

Unthinkable not to turn with an idea like that in her head; not to whimper when a dark shape plainly is moving closer. One of the tall stones has split in two like a splinter of rock breaking away from a cliff. The splinter stands free and steps forward.

She runs then, but not for long. Another black shape is blocking her path, cutting off her route to the bridge. She turns. Another. And another. Dark figures make their way towards her. Impossible to run. Useless to scream. All she can do is turn on the spot, like a rat caught in a trap. They take hold of her and drag her towards the great, flat rock and one thing, at least, becomes clear.

The sound she can hear is that of a blade being sharpened against stone.