The New Zealand Armed Offenders Squad (AOS) is an elite group of highly trained professionals, brought together in an emergency to protect the public from armed criminals, yet it is shrouded in mystery and myth. Born in the 1960s as a necessary response to random acts of violence, the AOS and the ultra-elite Anti-Terrorist Squad took on the burgeoning organised crime scene of the 1970s and the horror of Aramoana in the 1990's. Today the AOS remains as the Police frontline rapid response to protect the public from armed criminals. However in the changing world of the twenty-first century, threats to public order and safety have reached new heights and new responses are needed - the Special Tactics Group (STG) has been created to defend against and respond to possible threats from domestic terrorism as well as the most difficult armed confrontations. Written and illustrated from the exciting three-part TV documentary series, this is the dramatic inside story of a secret Police squad, told in full for the first time ever by the men who were there - in the Line of Fire.