Under Their Skin (Under Their Skin #1)

In this unpredictable thriller, 12-year-old twins investigate their new stepsiblings, only to discover that their entire world may be based on lies. Nick and Eryn are shocked to learn that their new stepfather has children (ones that neither he nor their own mother have ever mentioned), and they are downright baffled at their parents' insistence that the two sets of siblings never meet. Nick and Eryn take up the challenge to find out just what's going on, but the truth leads to bizarre revelations with far-reaching ramifications. Haddix (the Missing series) starts off conventionally, presenting the twins' situation as a family drama with elements of mystery, before gradually peeling away the layers to show a deeper, disturbing story that explores what it means to be human. Nick and Eryn are appealing, believable protagonists, though the supporting characters (particularly stepsiblings Ava and Jackson) aren't as fleshed out. Haddix's worldbuilding is solid, though, and her premise intriguing, raising many more questions than it answers while leaving the story open for further exploration. Ages 8-12. Agent: Tracey Adams, Adams Literary. (Jan.)

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. VERDICT Haddix offers a gripping blend of science fiction, suspense, and mystery, taking middle graders and teens on a fast-paced ride that will interest even the most reluctant reader.--Michele Shaw, Quail Run Elementary School, San Ramon, CA