Marin spends a lot of time avoiding things. She avoids thinking about her mother's suicide and what she could have done to prevent it. She avoids looking at people directly--because she can see their pain as bright, colorful shapes. And she avoids Cassie Jackson, who used her in a sinister ritual months ago, although Marin's not exactly sure why. When Cassie stands up at school, screaming, raking her nails down her cheeks, and pointing a finger at Marin, whispering "YOU," Marin's days of avoidance come to an abrupt end. Cassie's older brother believes that Marin holds the secret to Cassie's illness. So they team up to solve the mystery of what Cassie has unleashed. But as they look deeper into the darkness, can Marin trust what she sees?