Jon Klassen and Mac Barnett's latest collaboration is, as you might imagine if you've read any of their other books, not exactly your typical children's book. Triangle and his friend Square are devious little shapes, playing pranks on each other and wandering through a landscape of shapes and things without shapes. Is Triangle as smart as he seems? Is Square really as clever as he thinks he is? And more important- will Square get out of the spot he's in at the end?