For the first forty seconds, she watched a static shot of the shop’s front counter as a disembodied hand arranged special-offer protein bars and restocked a turning display of vaping liquids. At forty-seven seconds, a middle-aged man approached. Balding, with a taut beer belly and a smart-casual dress sense, he was average height and average in general, the sort of bloke no one would bat an eyelid at in the street. He’d pulled up the collar of his jacket against the rain, and his wedding ring caught the light as he placed three bars of chocolate on the counter and pointed to whatever he wanted the cashier to fetch for him. As a packet of cigarettes and a litre bottle of vodka were placed beside the chocolate, the man slipped his debit card into the reader and turned to address someone behind him.

Even though Rosie had prepared herself for seeing Kyle on the tape, his appearance was still unsettling. He slouched by the counter, twirling the vape display and pointedly ignoring anything the man said to him. His Superdry T-shirt and skinny jeans accentuated his slight build, the designer outfit at odds with his greasy hair and grimy face, as if someone had increased his clothing budget but hadn’t attended to his personal hygiene. He swiped the chocolate and the cigarettes, chewing one of the bars open-mouthed and shrugging off the hand the man laid on his shoulder. Seconds later, he flicked the wrapper to the floor and stalked out of shot. Evidently flustered, the man grabbed the vodka, with one eye on Kyle and the other on the card reader. He didn’t wait for his receipt. The paper fluttered to the counter, and Rosie jumped as a blast of static marked the end of the recording.

Too intrigued to worry about Steph barging in, she made another brew and rewatched the file several times. She jotted notes in bullet-point form, shaping theories and raising questions she had no one to discuss with. She closed the laptop when her eyes started to blur and the twinges in her arm grew into something with sharp needles for teeth. She felt dirty, as if the footage and all it implied had tainted her. They would find the man; the CCTV would provide excellent screen captures, and a public appeal featuring his image was bound to be successful. He probably had a family, perhaps a son of Kyle’s age who would have to go to school and explain to his mates exactly why his dad had been arrested. Within ninety minutes of eating that chocolate, Kyle had been dead: drugged and drunk, with his brain in bits. Rosie could still feel the flex of his ribs beneath the heel of her hand and see the utter hopelessness in Jem’s eyes.