A moment’s inspiration was never enough in police work. Generally, it had to be followed up by the painstaking slog of asking questions and making checks. And then sometimes it paid off. Paula might have scored the credit for inserting the idea of a portable anaesthetic machine into the investigation, but it had taken a hardworking detective constable bashing the phones all day to come up with the strongest lead.

He bounced up to Paula’s desk with all the abandon of a small boy who’s won a treasure hunt. ‘I’ve got a stolen portable anaesthetic machine for you,’ he said, waving a piece of paper at her.

She couldn’t help feeling a lift in her spirits. Sometimes the slightest forward motion in an investigation felt like a giant stride. ‘Good work. Where was it nicked?’

‘There was an emergency services conference five weeks ago at Manchester University. They had an exhibition hall full of stands for equipment manufacturers. Everything from ambulances to satellite radios. And a company that makes portable anaesthetic units had one that went a bit too portable, if you get my meaning?’ He grinned at her as he handed her the details of the exhibition. ‘It went missing overnight from their stand. They’d been using it to demo how it works on site.’

‘Did they report it to us?’

He shook his head. ‘The organisers persuaded them there was no point. They refunded their exhibitors’ fee, so the company weren’t out of pocket and the organisers didn’t have to deal with the embarrassment of having cops crawling all over their exhibition. That’s why it didn’t show up on our records.’

‘Fantastic. Well done. So, does anybody have any idea who might have nicked it?’ Even as she spoke, Paula knew it was too much to hope for.

Now he looked crestfallen. ‘If they have any suspicions, they’re not letting on.’

‘Have you got a map of the layout of the exhibition?’

His eyebrows rose in surprise. ‘Of course. No, I haven’t. I didn’t think of that. I’ll track it down.’

‘And a list of accredited attendees. One other thing – what about the gases that the machine uses? Did the thief get those as well?’

He nodded. ‘Apparently the machine was loaded up with the real thing. Bloody stupid, if you ask me.’

Paula sighed. ‘If you don’t expect to be a victim of crime, you don’t always take the sensible precautions. Still, nice work. Let me have a look when you’ve got that exhibition map. Plus a list of delegates and exhibitors.’