Ruby is a vlogger, a rising star of YouTube and a heroine to millions of teenage girls. And she's missing. She's an adult - nothing to worry about, surely? Until the video's uploaded. Ruby, in the dirt and pleading for her life.

Who better to head up the investigation than the Met's rising star, Detective Inspector Kate Riley? She's leading a shiny new team, high-powered, mostly female and with the best resources money can buy. It's time for them to prove what they can do. Alongside her, Detective Superintendent Zain Harris - poster boy for multiracial policing and the team's newest member - has his own unique contribution to make.

But can Kate wholly trust him and when he's around, can she trust herself? Ruby's millions of fans are hysterical about what may have happened to her. The press is having a field day and as the investigation hurtles out of control in the glare of publicity, it becomes clear that the world of YouTube vloggers and social media is much, much darker than anyone could have imagined in their worst nightmares. And the videos keep coming . . .