‘Maybe,’ PC Robertson replied, but Mark could tell by her tone she didn’t quite buy into his theory. ‘The family say Emily showed no signs of being in distress, mentally or physically; it was a normal evening by all accounts. No outward signs that she might harm herself, or that she was worried about something. She just disappeared overnight. No note, no nothing. Everything points to something else going on. Not just a… you know.’

Mark could see she didn’t want to say the word suicide, which meant she’d probably had a bad one recently. He was beginning to recognise these small signs, which made him feel better about himself. Like he wasn’t wasting his time with the career choice he’d made. Like he might even be good at it. ‘At the moment though, we have no evidence that anything has happened to her from an outside force.’

‘I suppose not,’ PC Robertson replied, barely above a whisper now. ‘Nothing ruling that out either, though.’

‘Hmm,’ Mark said, nodding to himself as he walked around the pool of blood, which had coagulated and stained the concrete. He’d seen stains like this before, so was pretty sure it wasn’t just an oil patch or the like. The CSI gave him the nod, just to confirm his suspicion.

Blood. But that wasn’t enough to start making assumptions, he reminded himself.

They were a good twenty feet away from the nearest wall, not exactly near the centre of the yard, but far enough away for it to tell Mark a few things. ‘If she was doing something to herself, I don’t think this would be the place. What, slit her wrists and then jump in the river? Or cut herself? Without her back against the wall or anything? It doesn’t seem right.’

Mark followed the few spots of blood that led away from the larger pool, watching as they grew smaller and eventually vanished. ‘They’re not leading to the water anyway,’ he said, turning back to the uniformed officers. ‘Over to that side, which doesn’t show a way out.’

PC Robertson hesitated, while the mute uniform standing next to her gave Mark a lazy shrug. ‘It might not even be her blood for all we know,’ he said finally, making a few notes to himself in his notebook. ‘At the moment, we need to concentrate on the fact she’s missing and that’ll have to do for now.’

‘You’re the detective,’ PC Robertson said, then turned away from him, following the path back out of the yard.

Mark stood for a few minutes, taking the scene in again, wondering what the hell he’d stumbled into here. Probably nothing, he thought. Yet, there he was – looking at a stain on the ground and wondering where a nineteen-year-old girl had disappeared to.