Beaton, M. C. Agatha Raisin mystery #33

"Agatha and her assistant, Toni, are driving to their friend Bill Wong's wedding when a terrified young man comes running the country lane toward them wearing nothing at all. The encounter leads them to become embroiled with a naturist group, a disappearing corpse, fantasy games, witchcraft, an ice cream empire, intrigue, and murder. In meantime, Agatha's private detective agency is as busy as ever and her private affairs are in turmoil. But when she begins to close in on a suspected murderer, she finds herself in deadly peril, as the sinister nature of the ice cream business leads her to a chilling conclusion"--