"A brilliant, necessary candle in the darkness." --Brendan Kiely, New York Times bestselling and award-winning coauthor of All American Boys and Tradition

From master storyteller and Printz Award-winning author An Na comes a dark, intensely moving story of a girl desperately determined to find a cure for the illness that swept her mother away, and could possibly destroy her own life as well.

Sixteen-year-old Grace is in a race against time--and in a race for her life--even if she doesn't realize it yet...

She is smart, responsible, and contending with more than what most teens ever should. Her mother struggled with schizophrenia for years until, one day, she simply disappeared--fleeing in fear that she was going to hurt those she cared about most. Ever since, Grace's father has worked as a recruiter at one of the leading labs dedicated to studying the disease, trying to lure the world's top scientists to the faculty to find a cure, hoping against hope it can happen in time to help his wife if she is ever found. But this makes him distant. Consumed.

Grace, in turn, does her part, interning at the lab in the gene sequencing department, daring to believe that one day they might make a breakthrough...and one day they do. Grace stumbles upon a string of code that could be the key. But something inside of Grace has started to unravel. Could her discovery just be a cruel side effect of the disease that might be taking hold of her? And can she even tell the difference?

With unflinching bravery, An Na has created a mesmerizing story with twists and turns that reveal jaw-dropping insights into the mind of someone struggling with schizophrenia.