The Innocent is the sixth episode of spook's fourth series which aired for the first time on 13 October 2005.
Summary
An Algerian army deserter and terror suspect, Nazim Malek is freed after two years in a British prison. Although he is found to be innocent, MI5 follow his activities, where they discover that he is being forced to conduct an assassination of an Algerian banker on British soil in order to guarantee the safety of his family.
The team save his family, who were held hostage, just before Malik could carry out the assassination and surrenders. In the end, he and his family have been granted asylum in Ireland.