Millie vs the machines

Within the confines of Oaktree boarding school, Millie Hendrick and her friends are privileged kids in a future world, where robots are hired help for everyone. But Millie has never trusted the Units. They're just ... creepy. When pupils start disappearing, and no one else shares her increasing terror, how can Millie find out whether she is the only person who can see the truth, or is simply going crazy?