After putting forward their concerns to Rumbold, the floor manager decides they should sleep overnight within the store, much to the staff's surprise, especially when he suggest they find suitable nightwear stock to use.
As part of a new promotion at the store, Grace Brothers hires an attractive saleswoman to sell a new unisex line of perfume and scents, dubbed "His and Hers", within the clothing departments.
The floor staff become upset when the saleswoman undercuts their own sales with special promotional freebies for passing customers, leading them to work together to sabotage the new venture.
However, in reality, the staff prove greedy and eager to claim the reward for themselves, especially when each group, including Rumbold, thinks they have found the missing stone on the floor.
At the same time, Rumbold is placed in difficult position of handing him a traditional cuckoo clock as a present, as it's usually given by Young Mr Grace to retiring staff.
To remedy this, Peacock has Brahms and Lucas switch departments for the day, unaware the junior male assistant will do anything to get out of work, faking an illness or injury with Mr Mash's help.
Following another day at the store, the floor staff attend an after-hours meeting with Rumbold to see what suggestions have been put forward to improve takings.
Young Mr Grace wants the Ladies' and Men's Wear department to form a ballroom dancing team to enter the national Golden Shoes Competition, and when a financial reward is offered all the staff are happy to take part.
Meanwhile, an Arab Emir arrives in the department wishing to buy a pair of trousers for one of his wives, but no one is allowed to touch her, so measuring her proves difficult.
(Several references were made to John Inman’s own appearance the previous year on This Is Your Life, including showing photos of the subject in short pants and ending up meeting Danny La Rue.)
Meanwhile, Mrs Slocombe and Miss Brahms argue when a customer (played by Tim Barrett) wants to buy two fur coats, one for his wife and one for his girlfriend.
Mr. Lucas wears a Jim'll Fix It badge around his neck, from the sequence in the children's TV show when a child's wish was to meet the cast.
After Captain Peacock returns sounding like Donald Duck and Mr Lucas with burnt feet, the staff are soon told that the Queen and the Duke of Edinburgh are making an official visit to the borough, and they might be coming to Grace Brothers.
The staff rehearse what to do if the Royal couple visit and on the day they all dress up in their finery and then watch them in the street below from Mr Rumbold's office window.
Unfortunately, just as it appears the Queen and Prince Philip might be about to enter the store, Mrs Slocombe accidentally knocks a plant pot off the window ledge which narrowly misses the Royal couple, who get back in their car and speed away from the scene as quickly as possible!
Mrs Slocombe becomes engaged to a Greek man called Mr Metaxas, and her wealthy American uncle Wendal P. Clark (played by Norman Mitchell) has offered to pay for the reception and will buy the couple a house as a wedding present.
However, on the morning of the wedding, the best man (Gorden Kaye) brings bad news: The groom is already married, and his wife has demanded that he return home to Greece.
After her co-workers fail to provide accommodation, Young Mr. Grace allows her to move into the store's Furniture Fitting Department on the top floor.
Mrs Slocombe turns the floor into a cosy home-from-home, but her space is soon invaded when a transport strike forces the rest of the staff to move in too.
Clearly relishing her new role, Mrs Slocombe holes up in Mr Rumbold's office, descending to the commoners only to flaunt her executive status.
Mr Goldberg is running a lucrative side business recruiting his colleagues for higher-paid sales positions in competing department stores.
Meanwhile, Mr Humphries contracts a rare tropical malady known as "Marine's Disease", and the entire staff are quarantined in the basement to prevent the infection from spreading.
Mr Humphries finds himself up to his neck with the gossip column, but his greatest challenge proves to be ensuring the staff bonuses by orchestrating a beauty contest with Miss Brahms as the ringer.
Mr Rumbold's brother Mycroft (also played by Nicholas Smith in a double role) then sets out to trace the Grace family tree, which leads to Wales, Scotland, Somerset and, ultimately (apparently), deepest Africa.
: This episode is sometimes omitted when the series is broadcast on TV due to the main cast performing in blackface, with the exception of Wendy Richard who apparently refused to wear the makeup.
With Captain Peacock acting as the prosecutor, Mrs Slocombe as Mr Humphries' defender, and Miss Belfridge being removed from the jury for being "biased", it's a trial to remember.
To their horror, the rehearsals accidentally get broadcast across London, prompting censorship threats and the wrong type of people coming to Grace Brothers.
Fortunately, Mr Humphries comes to the rescue as only he can, dressing up as an annoying female customer, prompting Miss Featherstone to leave.
Miss Bagnold is completely infatuated with him and when she joins the Grace Brothers Accounts Department and Captain Peacock soon finds his position unbearable.
Just when it looks like his career at Grace Brothers is finished, the perennially tardy Mr Spooner finds the rest of the staff competing for his favour after a record company offers him a contract after a brilliant performance at the Department Store Annual Concert.