Angela Hoot's unorthodox programming skills get her kicked out of MIT's graduate school-- and into the FBI's cyber-forensics unit as an intern. There's a messaging app with sophisticated tracking capabilities surfaces. Its beta users, all young women, are only identified as they turn up dead in their bedrooms. As Angela races to crack the killer's digital code, their technical rivalry escalates. She must deny the killer access to her personal life,...

"The woman's body was found in the early morning, on a bench in a New York City playground. She was clean, her hair neatly arranged, her makeup carefully applied. But other things were very wrong--like the tattoo and piercings, clearly new. The clothes, decades out of date. The fatal wound hidden beneath a ribbon around her neck. And the note: "Bad Mommy," written in crayon as if by a child. Eve Dallas turns to the department's top profiler, who confirms...