Did you know that a two-inch-high domino can push over another domino that’s one and a half times its size?

My Dad used to tell me that.

‘And…’ he’d say. ‘The next one can as well, and the next. And, you know what? If they keep going…’

click… click… click.

‘By number twenty-five you’ll be pushing over a domino the size of the Eiffel Tower.

And six after that? You’d better take a step back because one the size of Mount Everest will come crashing down and squish your feet.’

***

‘Miss Brown! Please!’

I’d meant to just leave the classroom. Calm down. Get some air.

I was angry.

And I was supposed to leave class when I got angry. That’s literally what the counsellor told me to do.

But when I slammed the door behind me…

… well, Mr Blakely should have just let me go. That was what he was supposed to do.

I raged off down the corridor, the sounds of that soft thud, gasp of pain, and the squeals of shocked students ringing in my ears.

How could I have gone back inside class after that?

Click…

I shoulder-barged the fire exit, blinking away daylight. Walked past a row of classroom windows, beyond caring who could see me. I was heading for the abandoned old house. The one place I needed to be right now. The one place no one would follow me. Let the anger go down.

But something stopped me in my tracks.

Two boys, deep in conversation, their backs against the wall of a History classroom.

Instead of veering past them, something about the way they were talking to each other made me pause.

Click…

If Blakely hadn’t said what he’d said about Dad, if I hadn’t felt the anger ready to burst out of me and run out of the room. If he hadn’t tried to follow me… then I never would have been at that exact spot, at that exact moment…

And none of this…

None of all this… madness… would have happened.

The two boys were so intent on whatever they were talking about that they barely even noticed me.

I already knew one of them.

Simon Taylor.

He was in my year at school: blonde hair, blue eyes — I mean, everyone knew him.

Definitely not the type to be skipping class.

The other one, I didn’t know. Not then, anyway. All I knew was that I’d seen him around before. He was a sixth former. Two years older than me and Simon.

Simon held something metal in his fingertips and they were hunched over it. Dead serious, as though they were planning a bank robbery.

Me. I was frozen to the spot. My body was still in flight mode, but something… some other feeling nailed my feet to the floor.

Something about what they were staring at.

‘No one else’ll come,’ Simon was whispering. ‘And you’ve been inside the grounds, haven’t you?’

The sixth former ran fingers through a mop of untidy hair. ‘Not inside though.’

‘Well, now you have your chance.’

‘It’s not called the Murder House for nothing, is it? The place’s a death trap.’

My eyes shot back to the silver object wriggling in Simon’s fingers.

A key.

‘That’s why I need you to go with me,’ Simon was saying, but…

click…click…

A key to the murder house?

The end of school bell ripped through the silence. It was quickly followed by the sound of voices and scraping chairs. Simon pocketed the key, pushed away from the wall and headed off. The older boy glanced at me for a split second, then went with him, blending into the sudden stream of blue uniforms that exploded out of a door further along.

I stood and watched them go.

Of all the things I could have stumbled on. Two boys with a key to the house.

The house.

‘Esta!’

Mr Blakely was staring at me from the fire exit, a bloody handkerchief pressed to his mouth where the door must have hit him.

I stared back, blankly. A whole row of ever expanding dominoes tumbling over in my mind.

At the time, I had no idea what had been set in motion. All I knew was that Simon Taylor was planning to break into the Murder House.

And, he didn’t know it yet, but, as sure as one domino flattens the next one, I was going in there with him.