December, and the river is rising. The village of Ledwardine has never been flooded in living memory. Within days it will be an island. There's no electricity. The church is serving as a temporary mortuary for two people who drowned. Only one man feels safer. An aggressively-atheist author has been moved, for his own safety, Rushdie-style, into a secluded house just outside the village. Fundamentalist Christians have hated him for years. Now he's offended the Muslims. Bad move.

Meanwhile, archaeologists, assisted by Merrily's teenage daughter, Jane, are at work in Coleman's Meadow, unearthing an ancient row of standing stones which some people would rather stay buried. The atheist's temporary home is close to the site, and his young wife is becoming conspicuously agitated. Is it the fear of discovery – or the kind of fear that she, of all people, could never disclose? One thing is clear – the last person who's going to be welcome in that house is an exorcist.

With the flood water washing up Church Lane towards the vicarage and the shop running out of cigarettes, it looks like a cold and complex Christmas for Merrily Watkins in an ancient community forced to untangle its own history against the swirling uncertainty of the future.