The widow of former Russian spy Alexander Litvinenko explains why she feels lessons weren’t learned between her husband’s assassination and the Salisbury Poisonings. Marina Litvinenko warns that British citizens need to be protected from foreign agents who ‘come to play their games’ in the UK and she recalls the moment she heard about the Salisbury nerve agent attack.

This episode was made by Marie Lennon, Andy Howard, Tom Ryan & Dan O’Brien.

Executive production by Mary Sanders and Naomi Wordley.