集数：
10集全
评价：
剧情：
bbbSeasonfourofespionagedrama"MI-5"findstheteamreelingfromthelossofDanny(DavidOyelowo),butthrownbackintoactionwhenabombdetonatesnearhisfuneral.ZafarYounis(RazaJaffrey)andJulietShaw(AnnaChancellor)areintroducedtotheshow,inastoryinvolvingapotentiallydevastatingterroristattackinthecapital.LaterintheseasonLyndsayDuncangueststarsasaformerMI-5officerwithadeadlygrudge,onewhichthreatensthelivesofeveryonebackatTheGrid.