Hermiony Vidalia Criony Fiddlestadt, aka Granny, and Jezabelle Jingle are supersleuths in their own communities, Granny from Fuchsia and Jezabelle from Brilliant. Because they live only twenty miles apart in rural Minnesota, they are careful not to encroach on each other's territory. Granny and Jezabelle both believe a rivalry exists on who is the better crime solver.

When Delight Delure, Granny's friend and Jezabelle's niece, sends them on vacation with the women's two best friends, Mavis and Lizzy, they don't know they will be actual cabin neighbors at Weed Lake in Northern Minnesota. During a skirmish with each other and an accidental plop in the lake, they find a dead body. Adding to the mystery are clues and puzzles left on their doorstep that may warn of danger and others that show friendship and caring. Which one should they believe? Are their lives in peril, or are they being pranked, and to what end?

The two cunning amateur sleuths work together to solve a murder that Sheriff Phil Puxatawny doesn't take seriously. But mayhem breaks out, having all four women wondering if they'll leave Weed Lake alive.