Written by Victor Pemberton
Directed by Hugh David
The TARDIS lands on the surface of the sea, just off the east coast of England. The travelers use a rubber dinghy to get ashore, whereupon they are shot with tranquilizer darts and taken prisoner.
They awaken to find themselves imprisoned at a natural gas refinery for trespassing in a restricted area. The Doctor learns that there have been a number of unexplained problems with the pressure in the feed pipes from the offshore drilling rigs, problems exacerbated by Robson, the ruthlessly driven head of the refinery. The Doctor uncovers that one of the rigs has sucked up a parasitic form of seaweed capable of releasing poisonous gas and emitting a strange foam allowing it to take control of people's minds.
The weed spreads rapidly, intent on building a huge colony centered on and around the rigs. The Doctor makes the discovery that it is susceptible to high pitched noise; consequently he is able to use the amplified sound of Victoria's screams to destroy it. Victoria, tired by the constant dangers in their travels, elects to remain with Harris, one of the refinery workers, and his family.
Although he shares Jamie's sadness at her departure, the Doctor understands her decision to settle down to a quieter life, and the duo sadly leave her to continue on their journey.
Like the vast majority of season 5, Fury from the Deep is a base under siege story. It's not a terribly versatile format, as its merits from a production side come from its limited locales and casts. There are ways to subvert these limitations and keep it fresh, largely through atmosphere, pacing and interesting supporting characters. The best stories of this season accomplish that.
Fury from the Deep is not one of those stories.
This is not to say that it's terrible. There are things to enjoy in this story, notably the creepiness of the two human antagonists, Oak and Quill. They are among the scariest villains of the era, and they are played extremely well and from what we've seen in the surviving clips, would have been genuinely terrifying. We also are treated to yet another unconventional female role in Megan Jones as played by Margaret John. Jones is the overall boss of the whole operation, and is played to be tough but fair. Today, this wouldn't be a surprise, but in 1968 Doctor Who it's a welcome development.
The fundamental problem that sinks (pardon the pun) this story is the fact that seaweed and foam make for extremely uninteresting villains. When the mind controlled humans are around, it works extremely well. There's an amazing scene where Harris' wife, possessed by the weed, simply walks into the sea. and that is sublimely creepy. And the climatic confrontation between the controlled Robson and the Doctor works well. But the rest of the time, everyone is running away from a bubble machine and unconvincing weeds.
There's a lot of padding and running around that accomplishes nothing. This is most evident in a long helicopter scene that appears to be solely about the Doctor flying loop-de-loops, a scene that comes smack in the middle of the climax and serves no narrative purpose.
Director Hugh David clearly does his best, as all the best elements seem to be directorial touches, but Pemberton's script can't meet him halfway. The most well-written stuff comes in the way the script handles the departure of Victoria. I've never thought she was a terribly well-written character as they mostly relied on her to scream and be terrified. She had a few good moments, and Watling played the role as written very well, but she was always too fragile for me to get behind. Still, her reason for leaving is entirely understandable, and the sadness of the Doctor and Jamie is obviously heartfelt.
It's definitely the weakest story of the season so far, but it does include the introduction of the Doctor's sonic screwdriver, earning it a place in the series history!