After the murder of a young mother in London, there's a climate of fear, and catching her killer becomes a national obsession. So police devise a controversial honeytrap fronted by a female officer.

The undercover operation gains momentum as prime suspect Colin Stagg starts to fall for covert officer 'Lizzie James'. But when the honeytrap is compromised, Detective Inspector Pedder must act fast.

While Colin Stagg is on remand in prison, another horrific murder occurs with some clear similarities. Is Stagg in fact an entirely innocent man?