I think my overriding memory of this story will always be the sheer creepiness of Mr Quill and Mr Oak. Even with only the brief Australian censorship cuttings available, they are very effective! They are very well spoken, they manage to talk simultaneously in a theatrical and clinical way. This is a story I would treasure if it came back.

The Doctor uses his sonic screwdriver for the first time when investigating the gas pipe at the beginning of the episode. It was heartening to see it actually being used to unscrew screws. There is indeed something to investigate - The Doctor detects a creature in the pipeline. We meet a ruthless drilling company and the man in charge will not stop drilling for anything, ignoring The Doctor's worries. Classic.

A side note. We have living seaweed breaking its way through the pipes multiplying and spreading a horrifying sickness which controls people. But once again; it looks like foaming washing up liquid, like the fungus in The Web of Fear - why?!

The overall feel of this story is very dark; its quite a brutal and scary story (which I enjoyed I should add). For example, we have an employee of the gas company whose wife is seriously ill who has to fight to leave work... this wife then goes on to walk into the sea and appear to drown herself. Meanwhile our friend Victoria is making it clear that she is not enjoying her time in the TARDIS she "just wants some peace and quiet". So much so that she would rather stay in a future time she has nothing in common with than go home, citing her lack of living family in her own time as a disincentive to go back. I hope she enjoys her life with the Harris's. It was a nice touch that Jamie and The Doctor stayed for another day in case she changed her mind. It did feel a tad sudden though and its odd that the Harris's would accept a relative stranger into their home so casually.

There were fun moments to be had too though - great seeing The Doctor fly a helicopter and a swim in the same story. Ha!