The task absorbed Judith all afternoon, but by 6 p.m. she realised she was feeling peckish. She’d recently been trying to shift a bit of weight, so she decided she’d have a poached egg on a single slice of toast for her tea. Then again, there was no way that one egg would ever be enough, so she had two eggs and plenty of butter on two slices of toast. And a few oven chips ‘to fill in the corners’ of her hunger, seeing as the rest of the meal was so healthy. And a nice cup of sweet tea and one of those super-tiny bars of speciality chocolate for her pudding, although she’d not been able to find one of the tiny bars when she’d done her weekly shop, so she’d bought herself a family size fruit-and-nut bar. Not that she’d finish it in one sitting, of course. It would easily last her the rest of the week.

Judith was just finishing the last square of chocolate when the local news started on her TV, and she was thrilled to see that the murder in Marlow had top billing. Putting her lap tray to one side, she grabbed a sharpened pencil from her crossword table and a pad of graph paper. On it she was then able to record the basic details: the victim was a local taxi driver called Iqbal Kassam who had apparently been shot that morning, and the police were asking for witnesses to come forward. It wasn’t much, Judith thought, but then she saw a brief interview with a woman who was filmed leaving the property with a Dobermann on a lead.

‘I’m not allowed to talk to you,’ the woman announced to the camera, but Judith could also see that she was delighted by the attention she was getting and desperately wanted to spill the beans.

‘But are you a friend of Mr Kassam’s?’ the interviewer asked.

‘My lips are sealed. You won’t hear a peep from me. Although I’ll tell you this much. Whoever did this to Iqbal deserves stringing up from the nearest lamppost. Come on, Emma.’

The woman walked off and Judith realised she recognised her. Not that she’d ever spoken to her before, but the woman often walked various dogs in the fields along the Thames Path that ran behind her house. She was a local dog walker, wasn’t she? And if she’d been visiting Mr Kassam’s house, then maybe she knew him well?