This was an interesting read with some unique elements and the possibility of more stories in the future. Eleven-year-olds Isaac Read and Wren of Snow are living with members of a different group in order to foster awareness and a strong relationship between their people. He's from the clepsit family, and she's a human, and both have their own struggles fitting in with their host families. Think of it as a sort of foreign exchange program that extends across a lifetime. When a group of voracans, prickly little beasts that look like a cross between a hedgehog and a pufferfish, decide to cause trouble between the two groups, the groups turn on each other. With war looming and Isaac kidnapped, Wren decides to see if she can do anything to calm things down. The book is filled with humor surrounding Wren's confusion about human ways. Despite the fact that she is human, she was not reared with clepsits, and she has no idea how to open doors or recognize objects common to everyday existence for humans. Isaac, on the other hand, has to cope with changing hair and skin color over the course of a year, forcing his family to move frequently. The prejudices both must deal with seem very real and might remind readers of their own assumptions about those who are unfamiliar to them. This was a fast and engaging read. I liked how the author included Mine, a chess-playing voracan with a heart.