A corrupt police detective has a painful moral awakening and decides to put right 20 years of wrongdoing.
Leila Farzad
Lucy Black
Olivia Nakintu
Carolin Stoltz
Andrew Buchan
Samuel Edward-Cook
Gavin Spokes
Mark Monero
Zak Ford-Williams
Anthony Lewis
Garry Cooper
Junade Khan
SISTER
BBC Studios
BBC One
