The future world is at peace.

Ella Shepherd has dedicated her life to using her unique gift--the ability to enter people's dreams and memories using technology developed by her mother--to help others relive their happy memories.

But not all is at it seems.

Ella starts seeing impossible things--images of her dead father, warnings of who she cannot trust. Her government recruits her to spy on a rebel group, using her ability to experience--and influence--the memories of traitors. But the leader of the rebels claims they used to be in love--even though Ella's never met him before in her life. Which can only mean one thing...

Someone's altered her memory.

Ella's gift is enough to overthrow a corrupt government or crush a growing rebel group. She is the key to stopping a war she didn't even know was happening. But if someone else has been inside Ella's head, she cannot trust her own memories, thoughts, or feelings.

So who can she trust?