Peyton's migraines won't stop . . . but they're not what they seem. Peyton isn't convinced when Miami police declare her sister Evelyn’s death part of a multiple suicide pact and close the case. So when the FBI reveal they believe Evelyn was murdered, and there could be a link to the recent FBI sting operation the sisters took part in, she agrees to work undercover at Etico, a California start-up turning the world of social media upside-down. But Peyton is also experiencing uncontrollable migraines . . . and they're becoming more frequent. Scientists are perplexed that her brain doesn't follow normal activity during a migraine attack—in fact, the two sides appear to be working independently of each other. As alarming discoveries are made at Etico, Peyton is sure these are not only connected to her sister's death but also her migraines . . . Can she find the missing link that will expose the truth? An enthralling read for fans of twisty high-stakes thrillers, technothrillers, and science fiction from Blake Crouch and Andy Weir.