Passing Strange (Vintage Paperback) by Catherine Aird (1982 Bantam Books)

In this gripping mystery by CWA Diamond Dagger winner Catherine Aird, the village spinster dies behind a fortune teller’s booth, and Calleshire’s greatest detective looks into the future—and sees justice

The annual Horticultural Society Flower Show would have gone off without a hitch were it not for one very pesky murder.
 
When nurse Joyce Cooper goes missing from the parish’s fortune-telling booth at the flower fair, her friends at the local church are immediately concerned. It’s not like this old lady, who plays the organ during service every Sunday without fail, and who, it’s told, lives for the purpose of helping others, to disappear without notice. So when she’s found strangled to death under a tarp, the community is thrown into an uproar.
 
Who better to calm the crowd than Calleshire’s greatest detective? Alongside his bumbling sidekick, Constable Crosby, C. D. Sloan runs through the bizarre list of suspects—the daughter of a deceased anthropologist, a greedy developer, a jealous tomato gardener, and a set of wealthy farmers—to find out who would have benefited most from the beloved nurse’s death. What he finds will astonish the entire village.