‘Plastic, seems to be the received wisdom. I spent an afternoon with Imperial College’s own resident expert, learning everything there is to know about tensile strength, durability and hysteresis on industrial meshes.’ She winked. A ripple of laughter washed around the room. ‘Aye, it was fascinating, but as I mentioned, probably not involved directly in killing him. But we don’t know who made it or why.’

‘What about the zoo angle? That seemed promising,’ Hoskins asked.

Gillard inclined his head sceptically. ‘DI Mulholland had a good look round. There wasn’t anything conclusive. When she was there, she did some random DNA swabs in bathrooms, on locks and gates, but we found nothing to match either of our victims.’

Rainy was looking down at her phone. ‘Hold on a minute,’ she said. ‘We just got a result, sir, from the stable isotope analysis. They know where our first victim lived.’ She scrolled down through the document on her phone.

‘Come on, don’t leave us all waiting,’ Gillard said.

She looked up. ‘Taiwan, sir. That’s where he grew up, but the minerals in his teeth and bones showed he spent some time in New York in later years, before returning to Taiwan.’

‘Right, now we’ve really got something to get our teeth into,’ Gillard said.

Chapter Twenty-five

The incident room meeting broke up and the detectives gathered round the email now showing on Rainy’s laptop.

‘That’s good news. It seems quite conclusive,’ Gillard said, reading through the list of minerals present in the bones of the man found on the island. ‘Carl, would you email the Border Force to see if any Taiwanese nationals arrived in Britain in the last three months. Then contact the national police headquarters in Taipei, and ask them about missing persons, copy in the British Embassy there. In fact it would be a good idea to get a complete list of anyone who bought an air ticket from Taipei to Britain in the last few months. The embassy might be able to help clarify who we need to speak to.’

‘Yes, I’ll get right on to that,’ Hoskins said.

Gillard turned to Rainy. ‘I still want you to put more work into the MO. If we solve that I think we crack open the entire case. It seems baffling to me that someone who may just have been a visitor to Britain happens to be slowly crushed to death.’

‘Aye, sir. It’s not just the method in common but the perpetrator. I can quite understand why someone would want to kill Neville Rollason, and presumably there might be someone who hates our Taiwanese fella enough to want to kill him. But who could possibly be involved in killing them both? It just doesn’t make sense.’