A spy, a nerve agent and a chilling diplomatic crisis. This year, a poisoning in the British city of Salisbury stunned the world. 

The former Russian double agent Sergai Skripal was the target of an attack involving the military grade toxin known as Novichok. 

It marked the first time since World War II that a chemical weapon had been deployed in Europe. 

TRT World'sSarah Morice reports.