From advice columnist Meredith Goldstein, a dazzling, romantic, and emotionally resonant YA debut about a teen science whiz in Cambridge, Massachusetts, who tries to crack the chemical equation for lasting love and instead wreaks havoc on herself and the boys in her life. For seventeen-year-old Maya, the equation for happiness is simple: a dream internship at MIT + two new science nerd friends + a perfect boyfriend = one amazing summer. Then Whit dumps her out of the blue. Maya is miserable until she discovers that her scientist mother, before she died, was conducting research on manipulating pheromones to enhance human attraction. If Maya can finish her mother's work, maybe she can get Whit back. But when her experiment creates chaos in her love life, she realizes that maybe love and loss can't be understood using the scientific method. Can she learn to trust the unmeasurables of love and attraction instead?

Sixteen-year-old Erin Misrahe just wants to be like everyone else in her new school. But Erin has more to worry about than passing AP Chemistry or making friends. In times of stress, she has always been overcome by her alter ego, Shevaun, whose violent behavior wreaks havoc on those around her. Erin can never remember anything about these episodes, and she’s grateful to have been spared them for a while. But when a protective friend comes back into Erin’s life, he insists that Shevaun is a vampire who actually exists apart from Erin. Shevaun has dangerous allies, like the handsome witch Adjila—and they’re determined to sever Shevaun’s connection to Erin once and for all.