Death and the Oxford Box

Dawn on a cold February morning and a mist hangs over Oxford, shrouding spires and domes. Feisty novelist Kate Ivory enjoys her early morning run with the (mainly) women's jogging group. It gets her away from her word processor and she hears all the local gossip on the hoof. This morning, one of the women complains to Kate that her husband has walked out on her, taking with him the valuable antique enamel mourning-boxes given to her by her grandmother who - horrors - is coming to visit. The group plans to nick the boxes back again. How could they guess that their amateurish raid would provide the cover for a more sinister crime?