She had soon realised she couldn’t just email out the stomach-turning pictures of the dead body to all and sundry in her search for an answer. It had taken some of the technical expertise of young Research Intelligence Officer Rob Townsend to alter the CSI images and electronically bleach out the human details so that all that remained was the pattern. Rob’s expertise on Photoshop had gradually turned the grisly image of a corpse into a rather beautiful 3D pattern, like violet wallpaper on a pale peach background. Looked at like this, there was a clear waviness that corresponded to the undulations of the now invisible flesh on which the marks were impressed. She had attached a scale to the side of the photographs, and then sent them off to the various obscure industrial academics who might know the answer.

The feedback had varied. Some blinded her with science, emailing back arcane papers and references without explanation. Others passed the buck to colleagues elsewhere, while a good half – this being the summer vacations – just didn’t reply at all.

The person she was now waiting for, Dr Marcus Goetz, was a researcher here at Imperial. The first person who claimed to have a clear answer.

Plastic.

She had been waiting fifteen minutes when she spotted Dr Goetz, talking to a receptionist. She’d looked up his picture on LinkedIn anyway, but the threadbare blue suit and woollen tie were as much a giveaway as the tatty leather briefcase, smeary glasses and the few tendrils of greying hair that had been combed across his balding pate.

Rainy went straight up to him and introduced herself.

‘Delighted to meet you,’ Dr Goetz said. ‘I think I’ve got something that will fit the bill perfectly.’ He shook her hand in both of his, then led her quickly along the front of the building, down another street and to a basement entrance. Rainy’s self-protection mechanism alerted her as the academic unlocked a steel door and showed her into a workshop the size of a triple garage. There were a few machines and consoles, but none of the presses or extrusion machines she had seen in her research.

‘Plastics are wonderful,’ he said. ‘Light, strong, stable and enduring. They are also now incredibly cheap.’ He went to a cupboard and brought out a few samples and laid them on a table in front of her. He produced an iPad and went to the sanitised victim photographs that she had sent him. ‘This is really a fascinating conundrum,’ he said. ‘The distortion is relatively modest and I presume unrelated to the force that you mentioned was exerted on the body.’