TheeighthseasonoftheBritishspyseries"MI-5,"whichfollowssecretagentsastheyfoilevilplotsaroundtheglobe,beginswiththefalloutfromHarry’skidnappingbytheRussians.Amysteriousorganizationknownonlyas"Nightingale"istheongoingfocusoftheeightepisodes.AndLucas’relationshipwithCIAagentSarahCaulfied(GenevieveO’Reilly),reignitesconcernsoverhisloyalty.Thisseasonalsoseestheexitofoneofthefeworiginalcastmembers,MalcolmWynn-Jones.