Thetenthandfinalseasonoflong-runningBritishespionagethriller"MI-5"seesHarryreturntohispostasheadofSectionD,whereinhisRussianoppositeIlyaGavrik(JonathanHyde)proposesastrategicpartnershipbetweentheircountries.New"spooks"ErinWatts(LaraPulver)andCalumReed(GeoffreyStreatfield)jointhefighttopreventallenemiesofthealliancefromsabotagingtheplanandinstigatingawar.