Annie is five when her beloved big sister, Gemma, leaves for school and is never seen again.

The police search for weeks and Annie never gives up hope that Gemma will one day come home to her. Now, twenty years after her sister mysteriously vanished, Annie returns to her childhood home to care for her ill mother.

Opening the door to Gemma's room, Annie finds it untouched from the day her sister disappeared, with her make up still on the dresser and her books open on her bed. Annie is certain that the answers to what happened to Gemma are here in her old room.

But in the search to finally find Gemma, will Annie discover her perfect sister is not who she thought she was? And will her quest for answers put her in deadly danger?

Someone knows the truth. And they will do anything to stop Annie from finding it...