In 1954 New Zealand Nellie and Daisy attempt to escape an institution for delinquent girls, however not only are they caught, it triggers a relocation to a facility on a remote island. The duo become a trio as well-to-do Lou joins them, and life on the island takes shape under the command of devout Matron. The trio rail against the system, dubious of the benevolence of the bible and taking refuge in their blossoming friendship. It’s hard to reform girls who don’t believe they need reforming. However, a sense of doom settles in when experimental forms of punishment take place in the dead of night. Nellie and Daisy plot rebellion, but unexpectedly find themselves at odds with Lou, who is afraid to break the rules.