Monarch of the Glen (2000)

S1E3 Episode 3

Tensions rise when Justine, Archie's girlfriend and business partner, arrives from London to investigate why Archie has been distant. She suspects he’s grown too fond of the local girl, Katrina. During her visit, Justine discovers a locked room at the estate that once belonged to Archie’s brother, who tragically drowned in their youth. The upcoming Glenbogle ball becomes the backdrop for a heated confrontation between Justine and Katrina, as emotions and rivalries come to a head.