Another American retail tycoon, Frank Woolworth, has come to London, and Harry and Rose host a dinner in honor their friend and his wife, Jennie. Harry has much in common with Frank Woolworth, the founder of the famous chain. But with a new Woolworth’s store set to open in Brixton, and a possible West End branch in the making, Harry’s feathers become ruffled. Afraid that Woolworth is going to gain an advantage on him, Harry wants Selfridges to compete with the famously low-priced department store. But to do so would require spot reductions on merchandise – it turns out you can't buy anything at Selfridges for a threepenny bit. When Miss Mardle suggests they hold a ‘mid-season’ sale, Harry loves the idea and runs with it, ordering window displays and doubling advertising space.
Back among those who needn't worry about a budget, Lady Mae is planning a soiree and is keen to introduce young Rosalie to some eligible young society men. Rose, who wants Rosalie to marry for love, not social position or money, is unsure. But she relents. Meanwhile, Tony Travers, Lady Mae's former lover, makes a surprise visit to the Palm Court with Ellen Love on his arm. They invite the very uncomfortable Harry to a new play Tony has written, in which Ellen stars, opening in a few weeks.
Meanwhile, Kitty and Doris are vying for Agnes' old job, senior assistant in accessories, and have to interview with Mr. Grove. Kitty approaches the interview with her usual confidence, while Doris, who brought Miss Bunting’s plight to Mr. Grove's attention, learns that Harry refused Mr. Grove's request that he give Miss Bunting a reference, since she’s fallen on such hard times. During her interview, Doris inadvertently reveals that her main ambition in life is to marry and have a family, which strikes a surprisingly emotional chord with Mr. Grove.
The ever-ambitious Victor has a proposition for Lady Mae: a restaurant space has opened up, and he wants her to back him. He makes her delicious Italian ice cream, which she agrees to showcase at her soiree – but she doesn't immediately back him in his venture. She will not be rushed.
Lady Mae’s soiree proves eventful when Harry bumps into Frank Woolworth, who seems to be taking the evening by storm, almost as if he’s vying for Harry’s place as London's own charismatic American retail tycoon. More eventful still is Rose's discovery of Rosalie sitting in a quiet room talking to a young man: Roddy Temple! Roddy charms Rosalie but still harbors feelings for Rose, which she is keen to dispel.
Henri prepares a romantic supper for Agnes, who is swept away by opera music and his seductive charm. She stays the night. The next morning, she takes him to an outdoor market to inspire him for the midseason sale shop windows. When she arrives home, she finds Victor waiting for her, feeling low after being let down by Lady Mae. She cheers him up and restores his confidence.
Frank Woolworth, whose wife is ill, puts off the opening of his new store and leaves London. Before departing, he confides to Harry that life is not about success; it's about family. On Sunday morning, the Selfridge family head to church, but Rosalie stays at home claiming illness. When Rose comes back early, she’s shocked to find Rosalie alone with Roddy, who is giving her a drawing lesson. Appalled at the impropriety, Rose throws Roddy out, asking him to never return.