Under Their Skin Books in Order

Under Their Skin is a two book series that starts as a blended family story and quickly swerves into science fiction. Twelve year old twins Nick and Eryn are still adjusting to their parents’ divorce when their mom announces she is remarrying. The unsettling part is not the move or the new house, it is the rule that they are never, ever allowed to meet their new stepfather’s children. (haddixbooks.com)

Curious and worried, the twins spy, sneak, and piece together clues until they finally meet Ava and Jackson and uncover the truth: humanity built incredibly lifelike robots, then panicked and tried to phase them out once human children were reintroduced. Nick and Eryn’s family includes both, and the four kids are caught between those who want cooperation and those who want either humans or robots erased. The sequel, In Over Their Heads, widens the focus as the joined family hides in a vast cave system and scrambles to stop old weapons and old fears from destroying what is left of the world. (haddixbooks.com)

The series keeps the chapters short and the action high, but underneath the chases and narrow escapes it wrestles with big questions about identity, prejudice, and what actually counts as a person.

Here you will find the books in order, an overview of the main cast on both the human and robotic sides, and guidance on themes that may be worth talking through with younger readers.