Coincidence or something more sinister? She had been able to establish that the victims had been killed at different times and had been dead for varying periods before they were discovered.

But what if something they had all eaten had triggered cardiac failure?

She blew out an impatient breath. She was being stupid. Of course they would have eaten something. Breakfast, lunch, whatever. But her instinct was nudging at her, urging her not to ignore this. It might be a waste of time, but it was worth a closer look.

She put down the reports and checked her watch. Technically, this could wait until morning but she knew she wouldn’t sleep. Her thoughts would whirl about in her head until she had satisfied herself that she was dancing up a blind alley.

Mathilda put on a plastic apron and a pair of gloves and headed for the refrigeration units, where she pulled out the metal tray containing the remains of Adam Stanton.

She tried not to look at his sightless eye sockets, the grayness of his face, the patchwork brutality of her own doing.

With careful fingers, she pried open his lips and shone a slim flashlight that she kept in her handbag into his mouth.

At first, she thought she was being stupid, and that her instinct had been way off base. The absence of his tongue had left a bloodied cavity that made goose bumps rise on her skin, she, the most hardened of them all.

She had checked his mouth, hadn’t she? But then she remembered that Wildeve Stanton had arrived and she’d been distracted, and now that she thought about it, she couldn’t remember anything about Adam Stanton’s teeth at all.

And what about the other victims? Clarity and focus were important parts of her job. But it was difficult to maintain 100 percent concentration at all times. Her focus had been on the heart and its surrounding muscles, the lungs and the oxygen levels in the blood. She had been so busy establishing a cause of death, looking in one direction for supporting evidence, that she had forgotten the basic mantra of her mentor, Dr. Sedrowski.

“Think outside the box, Mathilda. Dig a little deeper and instead of stones, you might uncover diamonds.”

She shone her flashlight onto the roof of Adam Stanton’s mouth, across the upper and lower jaw. At the back of his mouth, buried in his left molar, was a brownish speck. Using a pair of tweezers, she removed it from his tooth and placed it in a sterile plastic bag.

In the morning, she would order checks on the remaining bodies and their teeth, and closer analysis of the stomach contents.