Brendan Hughes wants to question Joe Fenton and find the “main mover.” Is Stakeknife suspected? We meet the former IRA man who interviewed Hughes and whose hero was Scappaticci.

Reporter: Mark Horgan
Produced and written by: Mark Horgan and Ciarán Cassidy
Co-Producer: Paddy Fee
Editing and Sound Design: Ciarán Cassidy
Composer: Michael Fleming
Sound mixing: Ger McDonnell
Theme tune by Lankum
Artwork by Conor Merriman
Assistant Commissioners for BBC: Lorraine Okuefuna and Sarah Green.
Commissioning Editor for BBC: Dylan Haskins