Prime Video's 'Young Sherlock' Just Set Up 8 Unexpected Season 2 Mysteries

Young Sherlock has reimagined the detective’s origin, showing a raw, unfiltered Sherlock Holmes (Hero Fiennes Tiffin) solving his first murder and stumbling into a global conspiracy. The season’s twists leave many threads unresolved and point squarely toward a potential second season.

One of the most striking choices was the instant friendship between Sherlock and a collegiate James Moriarty (Dónal Finn). That bond—equal parts camaraderie and friction—sets up a rich arc about why Moriarty becomes a nemesis. Finn said the best part of playing the character was “not making him a villain,” instead exploring him as an ambitious young man hiding hardships, which feeds the seeds of animosity and jealousy.

The final episode plants several clear mysteries: Sherlock decodes his father’s last words and finds a key hidden in a Charles Dickens novel, which Mycroft warned him to ignore but Sherlock uses as leverage over Moriarty.

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