Day 201: Fury From the Deep Episode 4

One of the things that characterises this point in the history of Doctor Who is the use of the formula of 'base under siege'. The premise of this is that monsters are attacking a closed room that is filled with some stock characters. The audience grows to know these characters over the month or so that they spend in their company, and also to fear the monster as it forms a presence over all that proceeds over the course of the episode. An example of this can be seen in The Ice Warriors, for instance, where a group of scientists were being held hostage by the evil Martians. Another example is here, where some oil rig technicians are being held hostage by weed. It's a nice set-up, because it allows for money to be saved on sets and actors, and it's also an effective way to create tension, by focussing not on simple scares of seeing monsters in front of your eyes (like has been done in previous episodes such as The Web Planet), but by instead keeping the monsters to a presence that controls the episode, the tension is able to be shown through the performances, writing and directing, which feels more realistic instead of relying on weird creature designs to see you through the remainder of the story.