The second series returned to UTV earlier this month and picks up the story of London's iconic Selfridge & Co department store, and its employees, five years later.
It's 1914 and Britain is on the brink of war and the future of the staff and the store is uncertain.
"So much has changed, and it's not just our hairstyles," says actress Amy Beth Hayes, who plays Kitty.
"We are coming in five years later so there have been so many changes in the characters' lives which I have found fascinating."
With war looming, the series, which stars U.S actor Jeremy Piven has the larger than life Harry Gordon Selfridge, focuses on the changing attitudes to the conflict as it progresses.
"There was almost kind of like a jubilant response (to the outbreak of war)," explains Aisling Loftus, who plays Agnes.
"It was very much like "our boys are going away" and the reality of that hasn't really hit anybody yet.
"But it does in this series."
In the new series, Agnes returns to Selfridge's fresh from her time in Paris to take up the highly coveted position of head of displays.
Loftus said: "She came back really excited and enthused about who she was planning to be and seeing all these people that know her who probably underestimates her vastly.
"And she enjoys being underestimated because she knows how good she is and how capable she is."
Meanwhile shop girl Kitty has been promoted to head of beauty, a department that has only just come to the forefront of the London shopping experience.
"In the first series beauty didn't exist as a department or a concept," explains Hayes. "It was always at the back of the store, it was very hush hush and it was very frowned upon.
"Even using moisturizer didn't happen, so when we start the second series that has completely changed.
"There's been a huge change in attitudes to women and how they present themselves and now beauty is at the front of the store.
"It's exciting for Kitty because she is at the forefront of that."