The Power Of Kroll is often cited as a below par Robert Holmes offering. While I agree it's probably not his finest hour I think it's far from his worst, (The Krotons, The Two Doctors anyone?). The storyline isn't the most gripping but it has alot of other things in it's favour. The excellent location filming is one of them, the marshlands of East Anglia looking convincingly alien and the soggy/rain-drenched atmosphere of Delta Magna comes across well on screen. I remember finding this story pretty scary as a youngster, the whole isolated refinery setting with a huge tentacled monster attacking it and our heroes trapped within was gripping stuff for a 5 year old. The model work for these scenes is actually really good and the Kroll monster very well realised. The only thing that lets it down is the blue screen/CSO work where you can see an obvious line between the monster and the horizon, but the creature itself is an excellent creation. The Swampies are an interesting race and the conflict between them and the Earth Men and Thawn's (racial) hatred of them is well portrayed. Thawn is a decent villain, played by the menacing looking Neil McCarthy, although it's a shame that Philip Madoc is wasted in a characterless role. Rhom Dutt is a good character but played so extremely laid backly by an actor who seems half cut most of the time (had he been spending some time in the pub with Tom?) Tom himself seems a little careless in this story, wandering through events taking everything less than seriously (at one point when someone offers him a cup of some drink he casually drops it into his pocket!)
This story does however feature one really clever scene where Romana is being menaced by what looks like a typically bad Dr Who man-in-rubber-suit monster that actually turns out to be a bad man-in-rubber-suit monster! A very clever in-joke?
A shame K9 couldn't take part in this story due to the boggy location, but overall The Power Of Kroll is actually a pretty entertaining if a sometimes rather silly for the wrong reasons story (check out the Swampie praying to a limp floppy tentacle in a pipe!) And anyway, how can you not love a story that features 20 odd half naked extras painted bright green dancing around in a marsh in East Anglia?