Sergeant Louise Nightingale is the model police officer; calm, composed and always in control. All that changes when she takes part in a police sing to trap the prime suspect in a series of killings. Suddenly, Nightingale is in the very nightmare world she tries to protect others from, and her worst fears are about to come true.

Sergeant Louise Nightingale is the model police officer; calm, composed and always in control. All that changes when she takes part in a police sing to trap the prime suspect in a series of killings. The killer has been preying on young women and Nightingale is the perfect bait, but nothing goes according to plan as she finds herself alone with the killer when her colleagues struggle to get to her in time, and she is attacked. Suddenly, Nightingale is in the very nightmare world she tries to protect others from, and her worst fears are about to come true.