Kathy and Callum successfully prevent a war criminal from leaving the country, but is he too important to prosecute? Callum is instructed to get rid of all information pertaining to individuals of interest, while also having to court the imperious Frau Bellinghausen - who holds the key to an infamous perfume.Callum juggles these new demands as his relationship with Rachel intensifies and becomes more compromising. Victor and Kathy make the most of his distractions to find whatever his department has been hiding.As Callum realises he isn't the free agent he has always believed himself to be, his dealings inside the hotel bring him closer to Harold, an ex-Foreign Office official and hotel regular, who reveals some startling truths about the outbreak of the war.Meanwhile, the friendship between Dieter and Callum is threatened when word gets out that Dieter may have stood by as innocents in labour camps perished under the rule of the Nazi party.