The only question now was who he could reach out to in a tentative approach. The Vance appeal would have reminded people of his existence. Maybe this was the perfect time to jog their memories a little more, to persuade them that he alone had something to throw into the ring that nobody else had. Not only did he understand how the mind of the serial offender worked; he was one of the few people on the planet who had actually been responsible for putting some of them where they could do no more harm.

It wouldn’t hurt to try.

That Monday morning in Berlin, Petra Becker was also thinking about serial offenders. It would be a terrific boost to her career if she managed to be the person who made the links that demonstrated there was a serial killer working across European borders.

But first she had to find the case she’d been reminded of. Petra sat and frowned at her computer, the severity of her expression a sharp contrast to the spiky exuberance of her short dark hair. Parallel lines furrowed her broad forehead and her eyebrows shadowed her blue eyes, turning them navy. She knew she’d read about it relatively recently, but she’d dismissed it as being of no interest. Petra worked in intelligence. Her team were responsible for gathering information on organized crime, building a basic case, then passing it on to the appropriate law enforcement bodies. With European borders allowing free passage to the criminal as well as the law-abiding following the Schengen Agreement, that frequently meant colleagues in other countries, often using Europol as a conduit. In the past three years, Petra had investigated areas as diverse as product tampering, drug running, credit-card fraud and human trafficking. Murder wasn’t normally on her beat, except when the investigating officers thought there might be a connection to organized crime. It was, she thought cynically, a way of handing off any difficult case that looked remotely like a scum-on-scum killing, the sort of scuzzy case that most police forces didn’t lose any sleep over if they couldn’t nail a culprit.

So the case she was looking for would have come in as a possible gangland killing. But if it had been tossed aside because it didn’t fit any of their parameters, it wouldn’t be in any of the holding files on the computer. It might even have been deleted from the main system, on the basis that it was just clutter.

Petra, however, was too anally retentive to dump case information without a trace. You never knew when something written off by everyone else might just feed into a subsequent investigation. So she’d developed the habit of taking brief notes even on the apparently irrelevant. That way, she could always go back to the original investigating officers and pull the details again.