Clarke brings the world of social media to this thriller.A 15 year old girl has been found dead after sending bizarre messages to her friends via Snapchat. To authorities, it looks like suicide, but when another girl disappears, police take notice. The missing girl is the sister of a Metropolitan police officer. DS Nareen Cudmore is determined to find her, the fact that the missing girl is part of the police family makes the search even more desperate. With journalist Freddie Venton at her side, Nas begins a search through the complicated and, in this case, deadly, world of social media.