Samantha Ruiz has a freak gene that makes her turn invisible, or ripple. She can’t control it, and it’s getting worse. Afraid of becoming a lab-rat, Sam keeps her ability secret, until fellow runner Will Baker sees her vanish into thin air. Will promises secrecy and help, and Sam begins to fall in love. Together, the two discover there are worse things than being a scientific curiosity. Someone’s been killing people who possess Sam's gene. A mysterious man from France sends letters that offer hope for safety, but also reveal a sinister connection with Nazi experiments. The more time Sam spends with Will, the less she can imagine life without him. When Sam uncovers secrets from her past, she must choose between keeping Will in her life or keeping Will safe