Out of Sight, Out of Time by Ally Carter

Cammie Morgan wakes up in an alpine convent with no memory of how she got there. The last thing she recalls is her plan to track down the mysterious organization known as the Circle of Cavan — but that was months ago. Now, she must piece together the lost fragments of her past and uncover the truth about what she’s done, where she’s been, and who she’s become.

As Cammie returns to the Gallagher Academy, her friends and teachers are no longer sure what to believe. The once bright and fearless spy-in-training is now haunted by what she might have discovered — or by what she might have done to protect those she loves. With enemies closing in and time running out, Cammie faces a mission that is as personal as it is perilous: finding herself before the past finds her.

Ally Carter’s Out of Sight, Out of Time is a tightly written, emotionally charged young adult thriller that combines espionage, identity, and friendship in equal measure. It’s a story about trust and transformation — and the cost of living a life built on secrets.