Under Their Skin

Gr 4–7—Twelve-year-old twins Nick and Eryn question their mom's claim that their lives won't change much after she remarries. How can that be when they'll be moving to a new house and they'll have two stepsiblings who will live in the house but whom their mom claims the twins will never have to meet? At first, Nick and Eryn have natural curiosity regarding their stepsiblings, Ava and Jackson, but before long their speculations turn into an all-out quest for answers. Something doesn't quite add up, and the twins conjecture there may be a more sinister explanation for secrecy. What Nick and Eryn uncover is so far out of the realm of their imagination, they cannot fathom their discovery. Ava and Jackson appear to be robots, and if that isn't puzzling enough, it appears their mom and possibly much of the human race may be as well. The siblings make it their mission to uncover the truth, and along the way, they realize they all may be in mortal danger. In true Haddix fashion, the story ends with a cliffhanger that will leave readers clamoring to find out what happens next in the series.