Upstairs, Downstairs (1971)

S1E5 A Suitable Marriage

In December 1905, Elizabeth becomes infatuated with a dashing young German baron, raising her father's suspicions. Richard soon discovers the Baron’s hidden truth, but it’s not long before Rose inadvertently uncovers an even deeper secret of Baron Klaus von Rimmer. The unfolding drama of the night drives one of the household staff to make a treacherous choice, leading to betrayal that impacts not only the family but the nation itself.