It’s happening again... Twenty years ago, on a remote farm out on the Thames estuary, six children were held captive for two weeks. Five of them got out alive. Now adults, they meet up each year to hold a vigil for their friend who died. But at this year's event, one of them witnesses a kidnapping. A young girl, Sammi, is bundled into a van in front of their eyes. Is history repeating itself? Is one of the five responsible? Or is someone sending them a twisted message? Only DI Sasha Dawson, of Essex Police, has the tools to find out. But with every second she spends trying to unlock the past, the clock ticks down for the missing girl...