Engaged in a police surveillance operation on the Somerset Levels, DC Kate Hamblin leaves the van momentarily and narrowly escapes death when it is blown apart by an incendiary device. Accused of abandoning two colleagues who died in the explosion, Kate is excluded from the resultant murder hunt and effectively suspended from duty. Anxious to nail the killer herself and clear her name, she risks all by entering into an unholy alliance with the murder team's chief suspect and finds herself not on