When terrifying evidence suggests the Orphans are part of a sinister ongoing experiment, Sarah’s suspicions turn to Paul, Beth’s boyfriend. But her probing inadvertently triggers Paul’s own investigation, bringing him dangerously close to the truth. Meanwhile, paranoid Alison piles on a whole new level of complication.

Sarah’s hunt for answers is interrupted by a trip to the suburbs. Alison’s paranoia has boiled over, putting all the Orphans at risk. But when Sarah, Alison and Beth’s worlds dangerously collide, Sarah must decide who to trust with her secret.

With Paul missing, Sarah is forced to confront the conspiracy head on. But when Paul learns Sarah has kept essential information from him, the fragile trust between them threatens to shatter. Meanwhile, Cosima grows closer to Delphine and the dangerously fascinating Dr. Leekie.

Sarah's actions pit the Orphans against each other as she tries to plan her next move. As Paul tries desperately to cover up Sarah’s existence, Alison takes vengeance on her suspected monitor, which could cost her everything she holds dear.

After two months of respite, Sarah’s hard-won refuge in Iceland is shattered by a Neolution attack. Once again forced to flee, she realizes no matter how far her family runs it will never be far enough.