Rate "The Mind Of Evil"

Who is Prof. Keller, and what is his machine that purportedly removes negative impulses from the brains of convicted criminals?  Well, Prof. Keller happens to be a certain nefarious Time Lord with a goatee (always a sign of evil), and his "Keller Machine" is, in fact, an alien mind parasite who renders the convicted criminals upon whom the device is employed as extremely compliant to the Master's wishes.  And his wishes involve a nerve missile aimed a peace conference.

So, what did you think of the second story of Season 8?

I think this one is pretty awesome as well!

I've never really been a fan of six-part stories, because at some point, they always feel like they're either deliberately padding the story with extraneous stuff, or they pull a fast one on you at the end of episode 4 and reveal the enemy behind the enemy. But this one sort of works.

4/5 from me.

I know folk are going loopy because of the re-colourisation, but it's an average story IMO.