TheeighthseasonoftheBritishspyseriesMI-5,whichfollowssecretagentsastheyfoilevilplotsaroundtheglobe,beginswiththefalloutfromHarryskidnappingbytheRussians.AmysteriousorganizationknownonlyasNightingaleistheongoingfocusoftheeightepisodes.AndLucasrelationshipwithCIAagentSarahCaulfied(GenevieveOReilly),reignitesconcernsoverhisloyalty.Thisseasonalsoseestheexitofoneofthefeworiginalcastmembers,MalcolmWynn-Jones.