Prime Video’s Young Sherlock follows a 19-year-old Sherlock Holmes (Hero Fiennes Tiffin) as he investigates his first case, but there are many twists and turns throughout the entire season. Based on the book series by Andrew Lane, Young Sherlock follows the detective fresh out of prison and sent to Oxford by his brother, Mycroft (Max Irons).
However, Sherlock isn’t there as a student but as an employee to clean and assist teachers around the school, but he still makes an impact with his high intellect. There, he meets James Moriarty (Dónal Finn), a student he quickly bonds with and also shows his high intellect, and the newly arrived Princess Shou’an (Zine Tseng). When a teacher is killed in Oxford, Sherlock becomes the prime suspect after being framed.
James and Sherlock set out to clear the latter’s name and find out who killed the teacher, and in the process, they learn the truth about Shou’an, make a shocking discovery about Holmes’ family, and uncover dark secrets involving Sherlock’s father, Silas (Joseph Fiennes).
Shou’an’s Plan In Young Sherlock Explained
Shou’an arrives in Oxford with important documents that belong to Chinese royalty. The events of Young Sherlock begin with the stealing of these documents from the university’s library and Sherlock being framed for it, as he and James had entered the library the previous night after crashing a party.
Shou’an, quickly noticing Sherlock’s brilliance, allows him and James to investigate the case, unaware that they will uncover her entire plan. As it turns out, the documents weren’t stolen, and Shou’an hid them in the library. This is supposed to be a distraction as she sets into motion a plan to detonate a bomb planted behind the library’s walls that would kill everyone in the adjacent room.
There, the ceremony for the new building in honor of Professor Bucephalus Hodge (Colin Firth) is being held, attended by all of Oxford’s teachers. Sherlock and James find this out right on time and save everyone, but that doesn’t stop Shou’an’s plans, as she then kills Professor Thompson and frames Sherlock.
After escaping from prison with Jame’s help, Sherlock and James find out that Shou’an is targeting a group of professors formed by Thompson, Malik, Roberts, and Enright, and though they try, they fail to save the latter two. Sherlock and James also find out the truth about Shou’an: she isn’t the real Princess, but an impostor, part of a group who kidnapped the princess on her way to Oxford.
The fake Shou’an is a young woman from a Chinese village in the Gansu corridor, who, one day, returns to find everyone, including her parents, dead. Shou’an is then recruited by Esad Kasgarli (Numan Acar), a man from Constantinople who offers her a chance to get revenge and kill the man behind the murders: Malik, who found a mineral in their land that he later turned into a deadly weapon.
The program to develop that weapon was paid for by the British government (who were also Mycroft’s employers, but he had no idea of this shady business) and run by Hodge, who was later betrayed by Malik, who sold the weapon. Also working in the development of this weapon were Thompson (math teacher), Roberts (engineering teacher), and Enright (meteorologist teacher).
However, Esad later tells Shou’an that they will no longer kill Malik and tells her that her job is done, so Shou’an realizes that Esad has been using her. Shou’an, Sherlock, and James later learn that Esad and Malik have been working together, and there’s a third, very important member in that team: Silas Holmes.
In the end, Shou’an gets her revenge against Malik and, with some extra help, destroys their underground lab. At the end of Young Sherlock, Shou’an returns to her village, where, to her surprise, her sister is back, alive and well, after she was severely injured by Esad when she and Shou’an confronted him.
Silas Holmes’ Experiments & Plan In Young Sherlock Explained
Sherlock and Mycroft’s father, Silas, is a brilliant scientist, but since the death of their younger sister, Beatrice, Silas had been mostly absent, while their mother, Cordelia (Natascha McElhone), had spent years in a mental institution due to grief. The big twist in Young Sherlock is the involvement of Silas in Malik’s weapon, Beatrice’s “death”, and Cordelia’s mental state.
Cordelia mentions a “man with the bird claw” to Sherlock and Mycroft, whom the former later finds out is Malik, as his cane has a bird claw. As it turns out, Cordelia is right in saying that the walls hear everything she says, as there’s a recording machine behind one of the walls, and all her conversations are being kept in a separate place.
The one behind all that is Silas, who planned the “death” of Beatrice to break Cordelia and send her to the mental institution, where he paid to have her drugged all the time to pretend she was mentally unstable. All this was so Silas could take control of Cordelia’s wealth, which she had before they got married.
Silas was in financial trouble before Beatrice’s “death”, but with the trust fund Cordelia’s father left for Sherlock and Mycroft, he recovered. Silas later bought Malik’s chemical weapon, which was the treason Hodge mentioned when confronting Malik, and with Esad and Malik’s help, he planned to sell it to the French.
This weapon is a deadly chemical intended to be used in armed conflicts, avoiding firearms and killing more people. With the help of the other professors, Silas planned to build a rocketship with which they could easily spread the chemical. In the end, and as mentioned above, Shou’an destroys Silas’ lab, but that might not be the end of his plans just yet.
Is Silas Holmes Really Dead At The End Of Young Sherlock?
Silas constantly lied to his family for years, and he doesn’t stop even in his final moments. Now with everyone against him, including Beatrice (Holly Cattle), Silas tries to pull one final trick. With nowhere to run and on the edge of a cliff, Shou’an and Beatrice are ready to kill Silas, but Sherlock decides he should face the law and the consequences of his actions.
Silas takes Sherlock, and they fight, with Silas letting go of Sherlock to let himself fall off the cliff. This moment is reminiscent of the famous Sherlock vs Moriarty confrontation at Reichenbach Falls, where both are believed to have jumped to their deaths in a physical confrontation. It’s later revealed that Sherlock survived and Moriarty died, so Silas could be pulling a fake death trick on his family.
What Really Happened To Sherlock’s Sister Beatrice
Silas made Cordelia, Mycroft, and Sherlock believe that Beatrice died 12 years ago when she wandered into the woods, an event that deeply affected Sherlock, as he felt guilty. However, as mentioned above, Beatrice’s “death” was an elaborate plan by Silas to take control of Cordelia’s money, and he counted on the help of the groundskeeper.
Silas told a young Beatrice to go into the woods, where the groundskeeper took her away and later delivered another girl’s body as Beatrice’s. Meanwhile, Beatrice was taken to another home, where she was raised by a childless couple. Silas remained as her benefactor, sending her a framed butterfly every year for her birthday.
Beatrice, who had grown up with repressed resentment and anger, set out to find who had been sending those gifts and found Silas, with whom she reconnected. Silas lied to her about her family and let her stay with him, aiding him in his different businesses. When Silas heard of Malik’s experiments and the program funded by the government, Beatrice posed as Hodge’s assistant to get information.
Cordelia and Sherlock try to make Beatrice see that Silas has been lying and manipulating her for years, but it isn’t until she hears Silas making the same promises he made to her to Sherlock that she finally understands.
Beatrice turns against Silas and tries to kill him before he falls off the cliff, and by the end of Young Sherlock, she’s free to do as she pleases, and she begins a secret relationship with James.
How Young Sherlock Sets Up Moriarty’s Villainous Turn
One of the biggest changes in Young Sherlock is the friendship and partnership between Sherlock and James. Sherlock and James make an excellent pair, with both being geniuses and using their combined intellect and talent to solve every mystery that crosses their path, and they end up learning a lot from each other (such as Sherlock learning how to fight).
Although Sherlock and James are friends throughout Young Sherlock season 1, the show sets up Moriarty’s villainous turn while they are in Paris. There, Moriarty is fascinated by Silas’ experiments and the chemical weapon, and is later morbidly fascinated by the death of a French soldier he kills to defend Shou’an.
In addition to that, James steals the equation for the weapon, under the excuse of keeping it so no one replicates it, and so they can find the counter equation for it. This sets up James’ possible betrayal, as it all points to him replicating the weapon at some point and turning against Sherlock, who wouldn’t be up for joining his plans.
What would add further tension between the former friends is James’ relationship with Beatrice, who, even though she’s now on the side of her mother and brothers, has proven to be as brilliant as her brothers, but not always with good intentions.
What Silas’ Hidden Key Really Means
Silas’ death doesn’t mean the end of his legacy nor the end of Sherlock’s family problems. Silas discreetly gives Sherlock his blood-stained handkerchief before falling off the cliff, which Sherlock believes to be a clue. After sharing his thoughts with Mycroft, he finds a key hidden in one of Silas’ books, with Mycroft asking him to let it go.
It’s later shown that Sherlock kept the key, but Young Sherlock doesn’t reveal what the key is for. It’s possible that the key will lead Sherlock to discover more of Silas’ dark secrets, which could be another secret lab or access to the documents of his many experiments. Whatever the case, Sherlock still has a lot more to learn about his father.
What’s Next For Sherlock & Moriarty After Young Sherlock Season 1
Young Sherlock perfectly sets up another season with Sherlock and James teaming up again – however, this dream team might not last for long. As mentioned above, James’ villain turn has already begun, and season 2 of Young Sherlock could see him setting his plans for the stolen equation into motion.
Meanwhile, Sherlock will surely continue trying to figure out why Silas led him to the key and what it is for, while investigating a new case with James. Young Sherlock season 2 will continue the family drama of the Holmes while Sherlock keeps on building his career as a detective, and James’ real intentions begin to come to light.
- Release Date
-
March 4, 2026
- Network
-
Prime Video
- Showrunner
-
Matthew Parkhill
-
Hero Fiennes Tiffin
Sherlock Holmes
-
Zine Tseng
Princess Gulun Shou’an





