China Lake by Meg Gardiner

What the cover says:
The Reverend Pete Wyoming is arming his flock - and not just with the scriptures. The way he sees it, the end of the world is nigh and he's ready for judgement. But judgement comes in unexpected ways...
Evan Delaney is shocked to discover that her ex-sister-in-law has joined The Remnant - Wyoming's fanatical band of disciples. And that Tabitha is trying to regain custody of her six-year-old son, Luke, currently in Evan's care while his father is posted to the Naval Air Warfare Center.
Two deaths and one kidnap attempt later, Evan realises she's started down a long road - the one to hell.

The religious group in this reminded me very much of the vile people in the Phelps' Westboro Baptist 'Church', and the hope of seeing them get their comeuppance keeps the pages turning! I frequently felt like I was holding my breath waiting to see what would happen next, and it was often the unexpected. A good read.

8/10