They sat, separated by two laptops on the kitchen island, the tapping of their keys in a pattern that fell in and out of unison.

‘You’re going too fast,’ Pip said to Ravi, peering at him over the top of her screen. ‘We need to look carefully at each one.’

‘Oh,’ he said sarcastically, pulling the accompanying face. ‘Didn’t realize we were looking for clues in the night sky.’ He turned his laptop, showing her four consecutive photos of the Chinese lanterns floating against the darkness.

‘Just checking, Grumpus.’

‘That’s my word for you,’ he said. ‘You aren’t allowed to have it.’

Pip went back to her screen, clicking through the photos and videos that had been emailed over by calamity-goers. Ravi was going through the memorial photographs, more than two hundred sent in already.

‘Is this the best use of our time?’ Ravi skipped quickly through another sequence of photos. ‘We know Jamie went to the calamity party after the memorial, and now we know he left there, alive and well, at half ten. Shouldn’t we be trying to track down his movements after that?’

‘We know he left the calamity party,’ said Pip, ‘but we still don’t know why he was there, which is strange enough by itself. And then add to that the phone conversation George heard. It’s all behaviour that’s very out of character, I mean, you saw Connor’s face when I told him. It’s weird. There’s no other word for it. Jamie’s behaviour starting from the memorial is weird. It has to be relevant to his disappearance somehow.’

‘I guess.’ Ravi returned his gaze to his laptop screen. ‘So, we’re thinking Jamie spotted “someone” – whoever they are – at the memorial. He found them in the crowd and waited, then he followed them when they walked towards Highmoor and into the party. Gropey Stephen said it looked like Jamie was just standing there, watching?’

‘I think so.’ Pip chewed her bottom lip. ‘That makes most sense to me. Which means that “someone” is most likely a person at school, in my year or maybe year below.’

‘Why would Jamie follow someone from your school?’

Pip picked up on the uneasiness in Ravi’s voice, though he tried to disguise it. She felt an instinct to defend Jamie, but all she could say was, ‘I really don’t know.’ Nothing about it looked good. She was glad she’d sent Connor home with a four-page printed questionnaire about typical password elements, for him and his mum to try on Jamie’s computer. It was harder to talk about Jamie with him right there. But Pip was struggling to accept it too. They had to be missing something, something that would explain why Jamie had been there, who he was looking for. It must have been important for him to blow Nat off and ignore all her calls. But what?

Pip glanced at the time on the bottom right-hand corner of her screen. It was half four now. And with Jamie’s new last-seen-alive-and-well time of 10:32 p.m., he’d now been missing for forty-two hours. Just six hours to go until the forty-eight-hour mark. The mark by which the majority of missing persons had returned: almost seventy-five percent. But Pip had a feeling Jamie wouldn’t be one of those.

And the next problem: Pip’s family were currently out at the supermarket, her mum had texted to let her know. She’d avoided them all day, and Josh had gone with them, so he was bound to cause some delay with all his impulse buying (last time he’d persuaded Dad to buy two bags of carrot sticks, which went to waste when he remembered he didn’t actually like carrots). But even with Josh’s distractions, they’d be home soon, and there was no way they hadn’t seen Jamie’s missing posters by now.

Well, there was nothing she could do, she’d just have to deal with it when they got back. Or maybe avoid it even longer by insisting Ravi never leave; her parents probably wouldn’t yell at her in front of him.

Pip clicked through more of the photos sent in by Katie C, one of the six Katies in her year. Pip had only found evidence of Jamie in two photos of the many dozens she’d been through so far, and one wasn’t even certain. It was just the lower part of an arm, peeking out behind a group of boys posing for a photo in the hallway. The disembodied arm wore a burgundy shirt that matched Jamie’s, and the boxy black watch he’d had on too. So, it probably was him, but it gave her no real information, other than Jamie had been walking through the party at 9:16 p.m. Maybe that was when he’d first arrived?

In the other you could at least see his face, in the background of a photo of Jasveen, a girl from Pip’s year, sitting on a blue-patterned sofa. The camera was focused on Jas, who was pouting in exaggerated sadness, presumably because of the huge red drink stain down the front of her once very-white top. Jamie was standing several feet behind her, beside a darkened bay window, a little blurred, but you could pinpoint his eyes, staring diagonally out the left side of the frame. His jaw looked tense, like he was gritting his teeth. This must have been when Stephen Thompson saw him; he did look like he was watching someone. The metadata said the photo was taken at 9:38 p.m., so Jamie had been at the party for at least twenty-two minutes by this point. Had he stood there that whole time, watching?

Pip opened another email, from Chris Marshall in her English class. She downloaded the attached video file, replaced her headphones and pressed play.

It was a series of stills and short video clips: it must have been Chris’ story on either Snapchat or Instagram that he’d saved to his reel. There was a selfie of him and Peter-from-politics downing two bottles of beer, followed by a short clip of some guy Pip didn’t recognize doing a handstand while Chris cheered him on, voice crackling against the microphone. Next a photo of Chris’ tongue, which had somehow turned blue.

Then another video clip, the sound exploding into Pip’s ears, making her flinch. Voices screeched across each other, people loudly chanting, ‘Peter, Peter,’ while others in the room booed and jeered and laughed. They were in what looked like a dining room, chairs pushed back from the table which was set up with plastic cups assembled into two triangles either side.

Beer pong. They were playing beer pong. Peter-from-politics was on one side of the table, lining up the shot with a bright orange ping-pong ball, one eye screwed shut as he focused. He flicked his wrist and the ball flew out of his hand, landing with a small splash into one of the outlying cups.

Pip’s headphones vibrated with the screams that erupted around the room, Peter roaring in victory as the girl on the other side complained about having to down the drink. But then Pip noticed something else, her eyes straying into the background. She paused the clip. Standing to the right of the bi-fold glass doors into the dining room was Cara, mouth wide as she cheered, a wave of dark liquid erupting out the top of her cup in this frozen moment of time. And there was something else: in the bright yellow-lit corridor behind her, just disappearing beyond the door, was a foot. A sliver of leg in jeans the same colour Jamie was wearing that night, and a white trainer.

Pip scrolled the video back four seconds, back to before Peter’s victory. She pressed play and immediately paused it again. It was Jamie, out in the corridor. His edges were blurred because he was mid-walk, but it had to be him: dark blonde hair and a collarless burgundy shirt. He was looking down at the dark object clasped between his hands. It looked like a phone.