She hurried up the stairs to the octagonal gallery where the local collections were kept. Bookshelves lined the walls from floor to ceiling, starting with ancient leather spines at one end and travelling through a chronological catalogue of book bindings to privately published memoirs bound with adhesive cloth tape.

At the far end stood a line of angled wooden tables, designed so that a person could sit and browse the large bound volumes of the newspaper collection. Here, this year’s copies of the Bradfield Evening Sentinel Times were fastened together week by week, clamped in place between long thin wooden batons. Carol found an empty chair and logged in with her tablet to the library’s wifi. Then she settled down with the previous week’s papers, working backwards from the day before Nadia Wilkowa’s disappearance.

She pored over the news pages, checking even the shortest snippet of news. Then she moved on to Births, Marriages and Deaths. She’d settled on fifty as a sensible upper-age limit for her target. Whenever she found a woman in the right age group, she turned to her tablet and went to the online edition for the day in question. A few months before, the BEST had started offering those who placed notices in the BMD section of the paper the opportunity to post a digital photograph in the online edition. It was a clever marketing ploy – it cost the paper nothing, but it generated a huge amount of goodwill. Now, when people died, their families and friends chose their favourite photo and uploaded it to the BMD pages online. So Carol was able to ascertain quickly whether the dead women were blondes.

It was a slow, painstaking process. By lunchtime, she only had two potential candidates. One had died, aged forty-four, ‘after a long battle with cancer. Beloved wife of Trevor, mum to Greta, Gwyneth and Gordon, gran to Adele. Much missed by her dear friends from the Fleece darts team.’ Her blonde looked as if it had come from a bottle. Somehow Carol didn’t think a killer with the control-freak tendencies Tony had outlined would allow his wife to join a pub darts team.

The other was, on the face of it, more promising. The woman was thirty-five and she’d died with her two small children in a motorway pile-up on the M62. Carol reckoned from her colouring that she was a natural blonde. There was no BMD announcement, just a news story about the accident. A lorry driver had been critically injured and two other motorists hurt in the late-night collision. An eye-witness said the lorry had appeared to swerve without warning across the outside lane before smashing into the crash barrier. The photograph of the woman showed her holding a baby on her lap with a toddler cuddled into her side. To Carol’s eye, she didn’t look very relaxed. But people often didn’t in posed photos.