Four brutal sadistic murders in multiple locations throughout the UK and committed by four totally different women, according to many reliable witnesses, have the Police Forces baffled. Investigations in all cases have come up against brick walls with no killers apprehended and all at dead ends. All attacks are identical in method, weapon used and victims, suggesting perpetrators are linked in some way, could it be a vicious female gang. The latest incident draws a tough no nonsense Chief Inspector with a dedicated team of detectives who are determined to bring the killers in. They follow clues that drag them all over the UK as they doggedly follow their investigations relentlessly. The murders also raise the interest of MI5 who recognise both the weapon and method as those taught to assassins in their service. Thinking it could be one of theirs gone rogue another team of dedicated hunters take to the field. It is their aim to nullify these targets before the public realise the ramifications and their involvement is made public. Two fearless teams tracking the same killers with different ends in mind create chaos for their leaders one of which is located in both teams. Rory Glassen must tread carefully to protect his identity is not blown by the police before the killers are eliminated by his MI5 squad first.