Mr. Selfridge recounts the real life story of the flamboyant and visionary American founder of Selfridge's, London's lavish department store. Set in 1909 London, when women were reveling in a new sense of freedom and modernity, it follows Harry Gordon Selfridge ('Mile a Minute Harry'), a man with a mission to make shopping as thrilling as sex. Pioneering and reckless, with an almost manic energy, Harry created a theater of retail where any topic or trend that was new, exciting, entertaining - or just eccentric - was showcased.
It's 1928 and nine years on, retail magnate Harry is enjoying his time at the heart of the Roaring Twenties. In store, while about to unveil a new monument he receives a very special visitor - though a later accident places his role at the helm in jeopardy. Elsewhere, Mr Grove celebrates his birthday in the company of his now 19-year-old daughter Meryl, and store favourite Kitty Edwards is keen to show off her luxurious new abode - while her sister Connie has some exciting news.
Following the Queen of Time unveiling accident, Harry recovers at his country home. However, keen to quash any retirement rumours, he returns to the store at the earliest possible moment intent on opening a cutting-edge technology department, and soon annoys Mae when he insists on a role for the Dolly Sisters at her first-ever fashion launch. Kitty is soul-searching after Connie's news gets around the store, while mysterious entrepreneur Jimmy Dillon starts to make his mark on Harry - not to mention Mae.
Despite his loss, Harry pretends that it is business as usual and is happy to be distracted by new belle Rosie Dolly. Kitty is nervous to meet her role model, cosmetics icon Elizabeth Arden, who is opening an historic concession in the store. Following a fall, Grove contemplates retirement and buys the family's first motorcar, while the launch of a joint venture between Jimmy and Harry leaves Gordon simmering.
After the huge success of the Selfridge Trust, Harry whisks a large group of journalists abroad to Biarritz for a typically decadent roaring twenties affair, which soon manages to get a little out of hand. Nevertheless, the retail magnate uses the occasion to announce that the Selfridge group has purchased a raft of new department stores across Britain. Meanwhile in London, the staff are preparing for a special visit by celebrated writer AA Milne, and Grove determines to continue with life as normal, until he gets a blast from the past.
The ground floor of the department store is transformed into a movie set, as Double Trouble starring the Dolly Sisters and famed-actor Bumby Wallace is filmed. Harry is delighted to be the source of excitement throughout London once again, as Grove and Mardle attempt to grapple with their past - and their future. Kitty comes to a horrible realisation, and Mae reconnects with old-flame Victor. Meanwhile, Harry's mistakes catch up with him in dramatic fashion.
Reeling from the bad publicity after the assault on the store, Harry finds himself forced to admit the true state of his financial affairs when D'Ancona piles on more pressure, and later finds himself embroiled in a costly spat with media magnate Lord Wynnstay. Mr Grove and Miss Mardle plan their very special forthcoming event, and Meryl enlists Tilly's help for a very important task - fuelling Miss Ellis' ire in the process. Mae and Victor grow closer, leaving Jimmy to become increasingly jealous.
Harry determines to get his life and the store back on track, and returns to what Selfridge's does best - a classic, store-wide summer promotion. However, he still has to contend with the disruptive antics of Lord Wynnstay, while a guilt-ridden Jimmy hides behind a daring new business proposition. Despite her grief and shock, Mae's new ready-to-wear summer collection proves a runaway success as Kitty's time at Selfridge's comes to a poignant end. Drama, starring Jeremy Piven, Sacha Dhawan and Katherine Kelly.
Harry, Gordon and Jimmy publicly announce the purchase of Whiteley's, claiming it to be an exciting project that will cement the future of the Selfridge legacy. However, while later helping out Crabb with the Whiteley's accounts, Harry makes a worrying discovery. Grove is forced to admit it's time to retire, while Meryl makes a stand to her father in order to get Tilly reinstated. Jimmy starts to arouse suspicions when questioned about Victor, and a sudden tragedy sends shockwaves through the store.
As preparations are made to celebrate the store's 20th anniversary, Harry works tirelessly to break the suppliers' embargo on Whiteley's, while Mae manages in avoiding him. A stoic Mardle struggles to cope, and Meryl steps in to provide some much-needed help. Jimmy's accountant reveals a massive problem, which leads to a very risky and secret plan, while journalist Joe Tooby continues to investigate him - with shocking results.
Harry's judgement, Whiteley's and even Lady Mae's love life are now all under the spotlight of a tabloid frenzy. Jimmy's final act has Harry reeling and the retail mogul retreats from the publicity for the sanctuary of home. Mae, now at the end of her tether, contemplates her future in London. The threat of a trade embargo imposed by Hardcastle sees acting boss Gordon backed into a corner, and Harry called to account.