These three episodes are on the second side of the first disc. It appears throughout that Watson is living in Baker Street, because there's no mention of his having a wife. However, there is a mention of Watson's practice in REDH, which sort of suggests that he lives or works elsewhere. But that dialogue is taken straight from the story, in which Watson says that he lives in Kensington.
The script writers also add more background information to the stories, such as how John Clay found out about the bank's French gold in REDH. Holmes also occasionally tries to prompt Watson to figure out details of the mysteries for himself, and he does manage it sometimes. Lestrade makes his first appearance in this TV series in SIXN, which is full of comical characters. But let's begin with COPP.
COPP begins with poor Alice Rucastle playing the piano until she collapses from exhaustion or brain fever. Meanwhile her father Jephro calls to the servant Toller to release the dog. Carlos (actually Carlo in the story) is a huge mastiff and certainly sufficiently threatening for Jephro Rucastle's sinister purpose. Next we see Mr. Rucastle at the employment agency, in Miss Stoper's office. He refuses one candidate, but offers the governess job to Violet Hunter as soon as he sees her. He tells her the extravagant pay, and the weird conditions of the job. He even mentions his photography hobby here. She of course refuses to cut her hair and leaves, while Miss Stoper disapproves.
Then at last we join Holmes and Watson at home, reading their newspapers. Holmes complains about criminals lacking any enterprise, then shows Watson the letter from Violet Hunter. She soon arrives for her appointment, but Holmes is still reluctant until he finds out about her case. Oddly, Watson remains standing all the while as she tells her story. The writers emphasize how smart she is, even having her deduce from Rucastle's letter that there was a first wife with whom he had his now grownup daughter. Holmes is very impressed, and Watson notices this. She also later proposes the theory that the second Mrs. Rucastle is crazy and that Alice won't humor her stepmother, so that's why she was sent to Philadelphia.
Finally Violet Hunter leaves to accept the job and cut her hair. After arriving at the Copper Beeches, she meets the horrid six-year-old Edward and doesn't like Mrs. Toller either. We get another scene at Baker Street, because Watson has checked out the will of the Alice's mother while Holmes sent a telegram to Philadelphia. (This solves a problem in the original story; a fortnight passes by and Holmes seemingly does no investigation despite his talking worriedly about Violet Hunter.) Watson asks about Holmes's interest in her, trying to encourage a romance.
Back at the Copper Beeches, more creepy things happen, and Violet investigates. Then we get an added scene where Jephro Rucastle and his wife Clara privately argue. Jephro claims that they only need to continue their scheme for a few more weeks, and then it'll be over. Clara protests that it isn't right or fair, and she implies that Violet Hunter will not survive another few weeks. I'm not sure if she means that Violet is going to be killed and have her identity switched with Alice so they can collect the money. (Or maybe, as implied later, Jephro is hoping that his stock investment will pan out and restore his money, and he's going to silence Violet for making trouble.) Either way, it makes Jephro much worse as a villain; all that bluster about paying her an extravagant salary becomes quite cynical, since they don't intend for her to enjoy it for very long.
Violet pretends to go into town to do some shopping, but really she's sending a telegram to Holmes. (Apparently, the writers have set this case in 1890, according to a notice on the wall of the Winchester post office.) She is seen, though, by Mrs. Toller and the bearded man. Holmes and Watson arrive, and we skip most of Miss Hunter's narration except for her complaints about little Edward's cruelty. Then the writers steal Holmes's own theory from the story, but modify it and give it to Violet instead. She knows that she's been brought to impersonate Alice Rucastle, and she fears that Alice has already been killed.
Holmes says that's one of his own plausible solutions to the mystery, but they need further evidence to narrow it down. So he sends her back to the house with a mission, apparently to count out the length of the house to look for hidden rooms. Rucastle catches her outside staring at the shuttered up window. He claims it's his dark room for photography, but is clearly suspicious of her cleverness. Violet doesn't sneak into the rooms by herself, as in the story; she just goes to meet Holmes and Watson again. (So does this mean that they stayed overnight at the hotel? How did she get permission to leave the house again, after Jephro got mad at her?)
Anyway, they conclude that Alice is actually alive and a prisoner in that secret room. They make their plans to free her, and lock up Mrs. Toller in the cellar. So that night, the Rucastles leave to visit friends, while Violet prepares for Holmes and Watson to arrive. They storm into the room only to discover Alice gone, and a ladder leading down from the skylight. Meanwhile, Jephro turns the carriage around, hoping to catch Violet snooping. He and his wife arrive, and he threatens Holmes and Watson angrily. Clara begs him to stop, but he goes for the dog anyway and gets attacked. Watson shoots it dead, and Violet leads the hysterical Clara away. Later, Watson reports that Rucastle will live, and Alice's bearded fiancé explains that he rescued her after bribing Mrs. Toller. Holmes suggests that Violet Hunter come back to London with them, but contrary to the story, she decides to stay for a few days since Clara is in no condition to watch over the boy Edward just now. Kind of noble and yet stupid, given that I wouldn't trust Rucastle not to attempt some kind of revenge on Violet if she stays.
But then! Holmes asks to speak to Violet Hunter in private, and Watson is looking very hopeful now. Later, on the train ride home, Watson asks Holmes about this conversation, and Holmes says, "She accepted." Watson assumes it was a proposal and starts to congratulate Holmes. But Holmes bursts his bubble, saying that he recommended Violet Hunter to Sir John somebody for a job as the headmistress of a school. Holmes says that she's young but should have a good career, provided that she avoids the trap of matrimony. Watson is clearly disappointed. :)
REDH begins at Mr. Merryweather's house, where he is having his usual game of whist. Unknown to him, John Clay and his accomplice are lurking in the study next door. They steal a bunch of stuff, and then Clay leaves a novelty pipe inside the safe as his trademark. The next day we see Inspector Hopkins (instead of Jones) with several more clay pipes as he asks Holmes for help on the case. Both Holmes and Hopkins know a great deal about John Clay's past crimes, so that I wonder again how come they can't find any proof against him. But Hopkins insists that they have to catch him in the act. I guess that's the best they can do, since Doyle didn't explain this point himself.
At Jabez Wilson's pawnshop, a Sergeant Jones shows a list of stolen items to Wilson. (Jones incidentally resembles Hopkins too much, so at first I was confused about why Wilson called him Sergeant. However, the end credits confirm that there are two different police officers. So poor Inspector Jones from REDH was apparently demoted in favor of Hopkins.) Anyway, Wilson complains that his shop assistant has suddenly disappeared, and that he's already begun advertising for a new one. Jones discovers that Wilson did receive one stolen article in his shop and that he was later given a forged banknote. Poor Wilson, but this must mean that John Clay has more accomplices than just Archie, or else they disguised themselves pretty well to not be recognized later. I also wonder if they're implying that Wilson's first shop assistant was kidnapped or killed so that John Clay could apply as Vincent Spaulding. The canonical story only suggested that Wilson couldn't afford to keep paying his last assistants.
Meanwhile, Holmes, Watson, and Hopkins check out the crime scene at Merryweather's home, but they can't go after John Clay yet. So at the pawnshop, Vincent applies for the job, and Wilson introduces him to the fourteen-year-old Mary Jane, who does cooking and cleaning. Later we learn that the girl is the daughter of an old shipmate of Wilson, and Vincent then shows them a photo he developed in the cellar. It's kind of creepy that they look like almost a cozy, happy family. Soon a month goes by, as in the story. I guess Vincent is learning the routine of the household and gaining Wilson's trust. Finally he shows the newspaper advertisement about the Red-Headed League, and drags Wilson there to apply. The Duncan Ross/Archie actor slightly resembles a redheaded Alan Rickman, but it's not him.
After the first day on the job we get a montage of time passing by at the pawnshop. There's no attempt to sort out the confused chronology of the story, but we do end with Wilson discovering the sign on the door on October 9, 1890. (Even though it's not a Saturday as Holmes claims.) Then we cut to Wilson showing this sign to Holmes and Watson, who burst out laughing. The scene is slightly out of order, though, because Holmes then asks Watson to deduce facts from Wilson's appearance. When Holmes deduces that Wilson has done a lot of writing lately, it's not so impressive since Wilson has already told them about his job copying out the encyclopedia. Bad story editor!
Holmes inquires about Vincent Spaulding and recognizes the description but we don't see Watson's face to know whether he recognizes it too. Surely in the months since the robbery at Merryweather's house, Holmes has described John Clay's scar and pierced ears to Watson? Anyway, when Holmes goes to the pawnshop later, Watson does appear to know that Clay is involved because he wonders what the "master cracksman" wants with the shop. Watson is smooth enough to not stare at "Vincent" weirdly when he answers the door of the shop. Still Holmes remains mysterious, not explaining why he tapped the pavement in front of the shop or why he just wanted to see the knees of Vincent's trousers.
They go off to violin land, and Watson watches Holmes enjoy the concert. Afterward, Holmes perceives that Watson wants to go home, so he lets him go for now. Watson promises to be at Baker Street at 10 pm, when Holmes needs him, and to bring his revolver. (This conversation is taken from the story itself, and thus carries the overtone that Watson does not actually live at Baker Street. Yet the characters do not behave that way in other scenes.) Holmes then goes alone to see Mr. Merryweather to discuss some important papers that were stolen from the safe; this is presumably how John Clay knew about the French gold in the bank vault.
That night at 10, Watson greets both Hopkins and Merryweather before Holmes appears. When they arrive at the bank, though, Sergeant Jones also brings Jabez Wilson to the gate. He says that Mary Jane is safe too, but doesn't mention where. I believe this is to refute Sherlockians who worried that John Clay would decide to murder Jabez Wilson and the girl that night to keep them from waking up and interfering with the tunnel robbery. So anyway, Wilson joins the group, and they wait inside the vault. John Clay finally breaks in with Archie, but they get captured.
Clay still indignantly says not to touch him and speaks of his royal blood before Hopkins takes him away. Clay even bows in respect to Holmes. Merryweather finally seems friendly and thankful. Holmes answers a few more questions for Wilson, then says that the case at least relieved his boredom for a while.
SIXN begins with Holmes working on the Conk-Singleton forgeries, but giving up in frustration. Watson reminds him that his lunch went cold because he worked all day. Holmes then starts cleaning up the papers and chewing on a cold drumstick, while Watson points out an unopened letter among the mail. It turns out to be a letter and a check from the Prince of Colonna. Holmes had attempted to solve the case of the Prince's missing black pearl a year ago, but did not succeed. How oddly generous of the Prince to send a check anyway. Holmes offers to take Watson out to dinner, but then Lestrade arrives, and Holmes tosses the drumstick into the fire.
Lestrade is played by Peter Madden, who does a good job in this and later episodes of the series. The inspector describes the first three smashed busts, and Holmes is so interested that he suddenly decides to skip dinner and go out to interview Dr. Barnicot. Barnicot is clearly a delusional Napoleon fanatic, so they leave as soon as they can. Back at Baker Street, Watson clowns around wearing Holmes's deerstalker sideways so he can imitate Napoleon. After that fun, they get serious again and discuss the idée fixe. Lestrade leaves them until the next morning when there is the murder at Horace Harker's house. Holmes and Watson then begin their investigation with the photograph of Beppo.
The writers eliminated the second shop that bought the Napoleon statues; instead Morse Hudson had all six, and sold five of them. Still, they investigate the manufacturer, and Watson is forced to buy a different bust that he leaves fingerprints on while it's still wet. Meanwhile Lestrade meets with Inspector Hill regarding the murdered man Pietro Venucci. There is also a rather long, silly scene in which Holmes and Watson meet with Josiah Brown, who owns the fifth Napoleon, and his irritating wife. Strangely, the writers omitted Lestrade's speech to Holmes about how Scotland Yard is proud of him. I guess they'd used up too much time in the episode to do it.
Holmes declares with satisfaction that they've clearly now earned the check from the Prince of Colonna. The final scene over the credits is Watson trying to glue the Napoleon bust back together. Why though? Holmes presumably is returned to working on the Conk-Singleton forgeries. Or else he's just sorting the mail.