Thestakesareraisedinseasontwoof"MI-5",asthethreattonationalsecurityincreasesandtheneedtothwarttheterroristsoperatingwithintheUKbecomesmoreurgent.TomisinvestigatingaSerbianterroristplot.HisgirlfriendandherdaughteraretrappedinTom'shousewithalap-topwhichisthought tocontainabomb.MeanwhileanotherbombisprimedtoexplodeandthisonekillstheSecretaryofStateforNorthernIreland.Addingtothepossibledangersfacedbyothergovernmentofficials,TomlearnsfromhisAmericancolleaguethatanassassinisintown,theCIAknowabouthimbuttheyhaven'ttoldMI-5.