But then the sound changes, morphing into an unmistakable grunting before the girl cries out. A sick feeling settles in my stomach and I feel myself frozen to the spot, the sound getting louder and louder until one of the men makes a long groaning noise followed by a brief silence.

Finally understanding where the noise is coming from, I lift myself up slightly and shuffle along on my knees, peering through a tiny gap between the wall and the back door. Pressing my eyes against the gap, I see an open window at the side of the building. Through it, I can just make out a mattress in the middle of the room, a camera set up at the side. The girl is sprawled across the bed, the men either side.

Before another second passes, I scramble to my feet. Moving as fast as I can back to the car, my fingers fumble with the key in the lock. Placing my foot firmly on the accelerator, I feel my heart beating in my mouth as I race through the traffic lights, towards home.

Chapter 41

Gabriela

Waves of nausea had already begun to pummel at her stomach as she arrived at the kids’ school for Sadie’s Christmas concert, having been waylaid by a sudden burst of sickness that saw her retching in the toilets of the pub just along from Kentish Town tube station. The following day, Tom would be taking the children to his parents’ for the weekend, but she had produced her usual excuse of work to justify staying in London.

The school was an imposing red-brick Victorian building with iron gates. She stood outside, waiting to be buzzed through, protecting her head from the light afternoon shower with her handbag. From the upstairs hall, she could hear the recital in full swing. Perhaps the noise was preventing someone inside from hearing the sound of her repeatedly pressing the buzzer. It was a momentary relief as she peered through the gate to spot Callum kicking a ball against the wall.

‘Callum?’ He turned and his mouth morphed into a smile at the sight of his mother. Reaching up to press the button to release the gate, he walked towards her and hugged her legs.

‘Baby, what are you doing out here? You’ve got no coat on, you’ll freeze. Where’s Daddy?’

Callum shrugged. ‘Upstairs, talking to someone.’

‘Why aren’t you up there? You mustn’t be out here on your own, anything could—’

She stopped herself, taking his hand and giving it a squeeze. ‘Don’t worry. Let’s go inside, yeah?’

Callum’s fingers tightened around hers as they moved into the building. Ruffling his hair with her other hand, she looked up, and instantly felt like she had been kicked in the throat.