Flamboyant Harry Selfridge, after transforming Chicago's Marshall Fields into a modern department store, realises London needs a modern store. He decides to build the biggest and finest department store in the world at the "dead end" of Oxford Street but his business partner pulls out of the project. Via a pressman he receives help from socialite Lady Mae Moxley and her contacts, one of whom invests in his plans. With his wife, four children and his mother arriving in London Selfridge begins to assemble his staff as the building is completed in record time.