The return of Archie's sister forces him into a big decision. Meanwhile, has Golly left it too late to admit his feelings?

Lexie discovers that Dorothy has annexed the island in the middle of the loch for a Tai Chi retreat. The island was a lucrative source of income for Glenbogle as it has the best fishing on the estate.Convinced that Dorothy waited for Archie to leave before trying such a stunt, Lexie decides to put up a fight. She and Golly concoct a plan to sabotage the retreat and win back the island. They succeed in scaring Dorothy's Tai Chi participants away, but when the ladies take the Glenbogle boat as well as the one they came in, Lexie and Golly find themselves marooned with a furious Dorothy.