Strike Back: Vengeance is the title of the third series in the Strike Back family of shows. / Series 1 (Chris Ryan's Strike Back) featured an ex SAS sergeant named John Porter who is recruited by a secretive arm of the military known as Section 20. Series 2 ( Strike Back: Project Dawn) still featured Section 20 but had an almost completely new cast led by Amanda Mealing (Holby City), Sullivan Stapleton and Philip Winchester (Camelot). Series 3 ( Strike Back: Vengeance) follows on directly from Series 2, but with minor cast changes.