About This Book

Spring semester at the Lab School in Hyde Park finds Petra and Calder drawn into another mystery when unexplainable accidents and ghostly happenings throw a spotlight on Frank Lloyd Wright's Robie House, and it's up to the two junior sleuths to piece together the clues.

Stir in the return of Calder's friend Tommy (which creates a tense triangle), H.G. Wells's The Invisible Man, 3D pentominoes, and the hunt for a coded message left behind by Wright, and the kids become tangled in a dangerous web in which life and art intermingle with death, deception, and surprise.

About the Authors or Illustrators

Blue Balliett

Blue Balliett grew up in New York City and studied art history at Brown University. Balliett and her family now live in Chicago. She taught at the University of Chicago Laboratory Schools before becoming a full-time writer.

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Brett Helquist

Brett Helquist is an illustrator whose work has appeared in books like Chasing Vermeer and Milly and the Macy's Parade.

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