Sherlock and the Sea Devils

This article originally appeared in Sherlock Holmes magazine issue #13, Summer 23.

The final episode of Sherlock, the third of season 4, was not received positively. (Well, final so far. Hope springs eternal in some hearts, with show creators still being asked “will there be a Sherlock season 5?”)

Many fans were dismayed by what happened in the episode, to the extent of pretending the show ended with season 3 (or even season 2, but that’s another topic). I’m not here to discuss the quality of that episode, though, but to point out an odd similarity with another TV show with similarly dedicated fans.

Let’s sum up that Sherlock series ender. In “The Final Problem”, Sherlock Holmes discovers that he has a previously unknown sister, Eurus. She is a manipulative genius, much more intelligent than other humans, able to bend people to her will to an extent that seems supernatural. She is held in a secret island prison, where she has taken over via mind control the government official supposedly in control of the location. She thus controls the prison while still appearing to be an inmate. Our hero and his sidekick have to infiltrate the location in order to … this is where the show’s logic is confusing, but basically, to bring the Holmes siblings back together.

Sherlock Holmes (Benedict Cumberbatch) meets Eurus (Sian Brooke) in “The Final Problem”

This episode has been criticized as being too “James Bond,” among other things, but I recently discovered a different potential influence that I found surprising.

The BFI showed on March 4, 2023, “The Sea Devils,” a 1972 Doctor Who story. It was scheduled to promote the Blu-ray release of Doctor Who – The Collection Season 9, starring Jon Pertwee as the Third Doctor and Katy Manning as Jo Grant. (Manning was even a guest at the event.)

I was lucky enough to attend, and while watching this serial, I noted a number of similarities with “The Final Problem”. In “The Sea Devils”, the Master (Roger Delgado), a manipulative genius beyond human intelligence, is being held on a secret island prison where he has used his superior mental powers to hypnotize the man in charge and his other keepers (and a race of aliens, the Sea Devils, as well). While he appears to still be an inmate, he’s actually taken control. Our hero and his sidekick have to infiltrate the prison to stop his plans and save the world.

Doctor Who (Jon Pertwee) and the Master (Roger Delgado) in “The Sea Devils”

(By the by, “The Sea Devils” is the only time during the Third Doctor’s run that Pertwee actually says “reverse the polarity of the neutron flow,” a phrase that became associated with him in fan lore and was reused in “The Five Doctors” anniversary special.)

The parallels become even stranger when I realized that this episode is the one that reveals that the Master and the Doctor had been at school together, so were youngsters at the same time, presumably. Although not ever part of the series, a popular fan theory was that the Master wasn’t just another Time Lord; he might even be related to the Doctor in some way, possibly his secret brother.

We know that Sherlock creators Mark Gatiss and Steven Moffat were Doctor Who fans. Moffat was in charge of the show from 2010-2017, and Gatiss wrote several episodes as well as An Adventure in Space and Time, the 50th anniversary film about the origin of the show. Gatiss went so far as to dress up as Pertwee’s Doctor for a promotional photoshoot for that film. He’s also aware of the Sea Devils, quoted as saying at the time of the recent episode “Legend of The Sea of Devils” they are “one of my all-time favourite monsters.”

Mark Gatiss as the Pertwee Doctor

Still, the plot parallels are probably nothing more than mere coincidence. The genius who’s forsaken humanity to hide out in an island fortress has been seen elsewhere, including in James Bond movies. While we can argue the suitability of the idea for the Sherlock series, it’s in keeping with modern adventure storytelling, where the villains have to get bigger and badder over a show’s run in order to keep audience interest. I did enjoy wondering whether “The Sea Devils” had crossed the writers’ minds when preparing “The Final Problem,” though.