When police clerk Isla Hoover's sister Mary invites her to play her bagpipes for a Wiccan celebration of Beltane, Isla's interested. She's looking forward to a peek at the May Day ritual of her sister's religion. But then Mary comes down with the flu, and Isla has to spend the long weekend on her own at the coven's Arizona camp.

Then the worst storm in decades takes out the only road to the Cave Creek Canyon retreat, and all of them are on their own. When somebody murders the May Queen, Isla's the closest they have to a police presence until the repair and rescue teams arrive. Will Isla's experience clerking for the Tucson Police Department be enough to figure out "who done it" and keep the rest of them safe in the meantime?