Margate, on England’s south coast. The hottest day of the year.

A derelict warehouse on an industrial estate. A woman claws desperately at the smooth, unbroken walls of a steel shipping container as it slowly fills with water.

She has six hours to live.

Her husband gets a chilling message on his phone: Drown The Rats. And a map. He races to the site. He sees his wife struggling for life . . .

Police Constable Abigail Morton is in her twenties, can’t find a man she wants to keep, and has just resigned after being passed over for promotion. Her special talent is getting people to talk to her, making her perfect for the role of source handler.

The one detective she really respects is DCI Paul Collier. And Abigail is the one person Collier needs in this case. When she gets the call from him, she’s back in.