I had an uncanny feeling while listening to this that I had heard it before - still not sure if I have, but I don't seem to have reviewed it, so possibly I'm going mad.
Anyway, Paul McGann is in fine form as the Eighth Doctor, travelling with Charley Pollard - they decide to travel to the Cimmerian System, to find out what happened, at one point in its history, to its sun. Meanwhile, on Cimmeria IV there is a small team setting up artificial suns - but it seems someone or something on Cimmeria IV is not keen to let the light in - at all - ever - and will do whatever it takes to stop them.
This four-part story ramps up the horror and suspense in the first episode, and then the second episode has the Doctor and Charley having their own little adventures - by the third episode things are, apparently starting to become a bit clearer to them, and to the scientific team from Cimmeria IV - but what has the Doctor not taken into account? The fourth episode wraps up all the loose ends - all a bit too neatly; I felt in some way slightly cheated that at the end it all just seemed to go away of its own accord. Great buildup; great premise; slightly off ending.
The Eighth Doctor is well characterised here; his horror at realising that he has interfered in something he should not have, is well portrayed, and fits the persona. Paul McGann is great as the Eighth Doctor, and the story (apart from the weak ending) really does play out well. R.O.S.M. is a great addition to the story; and Ian Brooker playing the part of R.O.S.M. does a great job. Definitely recommended.