We began the SHERLOCK season 4 finale on a plane, where a young girl with curls seemed to be the only person who was actually conscious. The girl answered a phone where the other speaker introduced himself as Jim Moriarty and welcomed her to “The Final Problem”.
Then we switched to Mycroft, who was enjoying an old black and white film — at least until old home movies kept flickering through. “I’m back” the screen read before the film flickered off.
Who is back? Clearly Sherlock and Mycroft’s sister, Eurus, who was introduced to us at the end of the last episode. Cornered in his home, Mycroft chased down a mysterious intruder who told him an “east wind” was coming. Soon Sherlock appeared and confronted Mycroft about the fact that they have a sister — and she has been incarcerated for many years. Enter John, who had only been shot with a tranquilizer by Eurus, but her reveal opened up a new problem for the men.
Soon Mycroft became John and Sherlock’s client and he was forced to tell the truth about their family because Sherlock confessed he no longer remembered Eurus. “You turned my sister into a ghost story,” Sherlock accused Mycroft of his east wind warning many years ago. But Mycroft insisted he was just monitoring his brother to ensure his true memories didn’t resurface. Apparently Eurus had been described as an “era-defining genius, beyond Newton” when they were children, but she was also incredibly creepy, having hidden and presumably killed Sherlock’s dog. Soon after Eurus had been taken to a maximum-security psychiatric hospital (Sherrinford) and Sherlock began repressing all memories of her. Mycroft and their Uncle Rudy even faked her death so that their parents would believe she was gone.
Mycroft insisted they could never have met Eurus in London, as she was still locked up tight in Sherrinford. But he realized soon how wrong he was when a drone carrying a grenade landed in the middle of Sherlock’s flat. Fortunately, all three men survived the horrible explosion, but we were soon whisked away to a boat, where the radio kept repeating the name Sherrinford. The fisherman in charge told his younger employee to just forget about the message, but Sherlock arrived to commandeer the boat.
At Sherrinford, the prison went into high alert as the boat approached and Sherlock left a message in the sand saying “tell my sister I’m here”. Sherlock managed to get a pass to the special security wing to find Eurus and inside her “Silence of the Lambs”-type cell he found a young woman playing the violin. Inside the governor’s office, Mycroft and John watched tapes of Eurus being psychologically evaluated. But how did Eurus manage to get out of Sherrinford? She “recruited” the shrinks sent in to evaluate her and got into their heads, forcing some of them to commit murder because, as Mycroft explained, she’s an expert in reprogramming people. And, in fact, she had enslaved the prison governor, who quickly turned on John and Mycroft and had them surrounded by security.
As to how Eurus got out, the truth is there was never any glass in her cell — it was just an illusion once she “took over” the prison via controlling the people who worked there.. Chaos soon reigned in the prison as videos of Moriarty played on the screen, Sherlock was attacked by his sister, and security swarmed over the three men.
Flash back to years before when Jim Moriarty was brought to Sherrinford to visit Eurus, courtesy of Mycroft. He was a Christmas present for Eurus, who was rewarded for using her brain to help with homeland security. Apparently she had requested 5 minutes with Moriarty because she knew he was interested in Sherlock. And soon she had everything she needed to know about how she and Moriarty could get the ultimate revenge on Sherlock.
Soon John woke up to find himself, Sherlock, Mycroft and the governor in Eurus’s cell. And then we were brought back to the first few moments of the episode, where the girl’s voice could be heard in the cell. Eurus soon cut off the girl, but gave the men an impossible choice — the governor had to die by John or Mycroft’s hand or she would kill the governor’s wife. Mycroft refused, so Sherlock turned the gun to John. But try as he might, John couldn’t do it, so the governor shot himself instead and his wife still died because John didn’t want blood on his hands.
Sherlock picked up the gun as instructed next by Eurus and then the three men left via a secret door opened by Eurus. They were reconnected to the young plane girl and tried to ascertain the plane’s whereabouts. But they kept getting cut off by Eurus, who made them solve puzzles to earn more “phone time” with the girl. Molly was then dragged in to the situation as Eurus made Sherlock call her to convince her to say “I love you” or she would die. But Molly didn’t want to say it, because it’s always been true. Crying, she demanded he say it to her first and he did. Fortunately, she said it as well, but Eurus had wanted Sherlock to get overly emotional and force Molly to confess her feelings, so he didn’t really win.
The next puzzle was even more demented, as Eurus demanded Sherlock kill either Mycroft or John. Mycroft immediately demanded Sherlock shoot John. But his coldness was on purpose, to convince Sherlock to kill him instead. Apparently Moriarty had been convinced a Holmes would kill a Holmes, but Sherlock nearly ruined his sister’s plan when he put the gun to his own head instead. After being knocked out by a tranquilizer courtesy of Eurus, Sherlock awoke to find himself on the line with the plane girl. John, meanwhile, was trapped inside a well, speaking to Sherlock, who was trying to multi-task with John and the girl.
It was soon revealed that Sherlock was actually at the old family estate — Musgrave — and Eurus instructed him to find Redbeard as John’s well filled with water and the girl on the plane plunged towards a city. Caught between two impossible problems, Sherlock was forced to choose who to save. But then the truth of Redbeard had come out — he wasn’t a dog, he had been Sherlock’s friend. Eurus had killed a little boy before burning down the family estate and that’s what got her locked away.
As Sherlock came to realize, the girl on the plane wasn’t real — it was a metaphor for Eurus feeling lost. He found her and comforted her, telling her she wasn’t lost and alone — and his love for her was what she needed to stop this horrible game. John was saved, Eurus was returned to Sherrinford and the Holmes parents were told the truth about Eurus. They were furious about what Mycroft had hidden from them all those years, but he told them there was no sense in seeing their daughter. Sherlock, however, visited her and played the violin.
John and Sherlock returned to 221B Baker Street to clean up the mess from the explosion and then a DVD featuring Mary arrived at John’s house. She told the men that she knew who they really were: a junkie who solves crimes to get high and a doctor who never really came home from the war. But all that mattered was the legend, the stories, the adventures. As Sherlock returned again and again to visit Eurus, he and John rebuilt their flat exactly as it had been before and life got back to normal.
Thus ends another chapter of SHERLOCK. There is no news about a season 5 of the show, but fans, I’m sure, always have their fingers crossed for more.