Petra, Calder, and Tommy are back with a labyrinthine new mystery to solve! When both Calder and a controversial Alexander Calder sculpture go missing, Petra and Tommy must fly to England to help find their friend. But this mystery has more twists and turns than a Calder mobile caught in a fierce wind - with more at stake than first meets the eye.

Blue Balliett is the author of several bestselling, acclaimed mystery novels, including Chasing Vermeer (a Book Sense Book of the Year and an Edgar Award winner), The Wright 3, The Calder Game, and The Danger Box. She writes in the laundry room of her home in Chicago, Illinois, and you can find her online at www.blueballiettbooks.com. Brett Helquist was born in Ganado, Arizona, and grew up in Orem, Utah. He entered Brigham Young University as an engineering major, but soon realized this was not the right choice for him. Having decided to take time off from college, he headed to Taiwan where he stumbled into a job illustrating English textbooks, which he enjoyed. There, a friend introduced him to an illustration student, also from Brigham Young University. This introduction inspired Brett to eventually switch majors. After spending a year in Taiwan, he went back to BYU and transferred to the illustration department. In 1993 he received a fine arts degree in illustration.