At Greenglass House, a smuggler's inn, twelve-year-old Milo, the innkeepers' adopted son, plans to spend his winter holidays relaxing but soon guests are arriving with strange stories about the house sending Milo and Meddy, the cook's daughter, on an adventure.

"Minerva Keen's life isn't exactly normal. But living in the luxurious Arcanum--with its interior balconies perfect for playing tag, an elevator like an iron birdcage, and quirky neighbors behind every apartment door--is more fun than normal. Until her neighbors start getting poisoned. Anyone could be next, and everyone is a suspect, including Minerva herself. To clear her name and help the police crack the case, Minerva starts her own detective club....