Get ready for your new obsession - pre-order the gripping new thriller from the No.1 Sunday Times bestseller Andrea Mara.Everyone has secrets. Even your daughter…The morning after a family wedding, Siobhan and Grace, her best friend of thirty years, go to the pool-house to wake up their twenty-four-year-old daughters, who are also best friends. Only they open the door and the room is empty - the girls have vanished without a trace.They search the house, the grounds, but neither girl can be found. Then Siobhan and Grace discover something shocking. Something inexplicable. Something that suggests one of their daughters is going to kill the other. And that’s before they find out what really happened late last night.They need to work together to find their daughters. But they can’t help but wonder: which girl is the killer and which is the victim?