Harry takes a massive gamble with the biggest flash sale in the store's history, while Nancy finds it difficult to keep their engagement a secret from Gus, and a meddling Princess Marie makes things even trickier when she starts to smell a rat. As Gordon and Grace try to get back on track, Violette is presented with a pragmatic life choice. Miss Mardle and Mr Grove come to blows again, and Loxley manipulates the board into making a decisive move against Mr Selfridge.