WithTridentrenewedforanothergeneration,AVeryBritishDeterrenttellsthestoryoftheremarkableevents,eye-wateringcosts,powerrelationshipsandsecretdealsdonehalfacenturyagotosecureBritain'sveryfirstsubmarine-launchednuclearmissiles. Intoday'sturbulentworld,itisastorythatismorerelevantthanever.AttheheightoftheColdWar,aseriesofpoliticalandtechnicalcrisescameclosetoleavingBritainwithoutanuclearweaponofitsown.Inatimeofunprecedentedinternationaltensionandwiththeworldlockedinaterrifyingnucleararmsrace,onesmalllochinScotlandbecameacrucialbargainingchiptokeepBritaininthenucleargame. Usingthepersonallettersofprimeministersandpresidents,eye-witnessaccountsandonce-secretdocuments,thisfilmexploreshowtheBritishprimeministerHaroldMacmillanseizedeveryopportunitytofurtherBritain'snuclearambitions,waspreparedtotradeaScottishbaseforanewAmericanweapon,andevenjeopardisedthecrucialAnglo-AmericanrelationshiptokeepBritainanindependentnuclearpower.